WASHINGTON -- In October 2011, John Canning, chairman of the Chicago-based hedge fund Madison Dearborn Partners, expressed his displeasure with President Barack Obama to the Chicago Tribune . "It's the populist economic policies of wealth redistribution and government control of all aspects of everyday life that I object to," he said.

Canning put his money where his mouth was, hosting a fundraiser for Republican presidential candidate Mitt Romney that fall. And Romney wasn't the only benefactor of his largess. Over the course of the 2012 election cycle, Canning gave to as many federal candidates, political action committees (PACs) and party committees as he seemingly could find -- some 38 individuals and groups, all but two of them Republican -- ultimately distributing $276,000 in contributions.

The sizable sum of those contributions appears to violate federal campaign finance law. Over the two years of the last electoral cycle, individual donors were allowed to give a total of $46,200 to candidates and $70,800 to PACs and parties, for a combined total of $117,000. Canning far exceeded those limits, giving $119,400 to candidates and $156,600 to PACs and parties. And Canning, who declined to comment for this story, was not alone.

A review of campaign finance records by The Huffington Post identified 49 individuals who donated more than $150,000 in the last election cycle, far in excess of the biennial contribution limits. Of the 49 donors, 48 exceeded the PAC and party limit and 32 exceeded the candidate limit. Most of them gave the lion's share of their contributions to Republican candidates and party committees. Canning gave the most of any donor noted by HuffPost. There are likely more who exceeded the contribution limits, but were not readily identifiable because of multiple problems with the way campaign finance data are collected.

The Federal Election Commission, which is responsible for enforcing campaign finance laws, does not have an efficient system for tracking donor contributions. The resulting lack of oversight and the clear violations of contribution limits mean that some 2012 campaigns artificially boosted their accounts and spent money they should not have received on advertising, get-out-the-vote operations and the like.

Some of the violations identified by HuffPost appear to have been caused by simple mistakes or confusion on the part of donors. But other contributions, like Canning's, do not look purely accidental.

"It's a real problem," Fred Wertheimer, president of the campaign finance watchdog Democracy 21, said about both the violations of contribution limits and the lack of oversight.

The law limiting overall contributions was enacted in 1974 and expanded in 2002 to prevent donors from writing million-dollar checks to candidates, which the Supreme Court has ruled could contribute to the corruption or at least the appearance of corruption of public officials.

Then the Supreme Court's Citizens United decision opened the floodgates ion 2010, allowing wealthy donors to contribute unlimited amounts of money to independent groups such as super PACs in order to influence elections. Casino magnate Sheldon Adelson, along with close family members, gave more than $100 million to groups opposed to Obama and other Democratic candidates. Still, super PACs operate nominally at arm's length from actual candidates, prevented by law from coordinating directly with the campaigns they support.

For all the focus on super PACs last year, the vast majority of campaign contributions continued to go to the candidates and parties themselves. Independent groups spent more than $1 billion in the 2012 election cycle, but the Obama and Romney campaigns raised over $2 billion, and congressional candidates raised $1.8 billion more. Canning, for his part, gave just $75,000 to super PACs during the 2012 cycle, compared to the $276,000 he gave directly to support mostly Republican campaigns.

Along with the billions pouring in, the costs associated with running a modern election campaign have increased substantially in recent years. And the additional spending brought about by the Citizens United ruling has left candidates and political parties scratching for more money, to protect against late-stage advertising by independent groups. This need for increasing amounts of money is likely one reason that so many donors are exceeding the contribution limits, as candidates and parties hit them up over and over for more cash.

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Source: Federal Election Commission

Park Corporation Chairman Raymond Park, who gave $120,800 to PACs and parties in the 2012 election, told HuffPost that he is receiving more fundraising requests than ever before. "It's just one thing after another," Park said. "Half my mail is just asking for contributions."

Soon the floodgates on direct campaign contributions may open as well. In its next term starting October 2013, the Supreme Court will hear a case challenging the constitutionality of the overall limits, brought by Republican donor Shaun McCutcheon and the Republican National Committee against the FEC. McCutcheon wants to be able to give as much as he pleases to candidates and parties, while the RNC would like to raise more money from top-dollar donors .

"RNC believes that other contributors would contribute to RNC but for the restriction of the biennial contribution limit, and it also wants to receive contributions from those contributors," the plaintiffs argue in their complaint.

When contacted by HuffPost, several donors explained that their excess contributions were the result of accidents and errors, made either by themselves because of their own misunderstanding of the law or by the committees to which they made contributions.

George "Brint" Ryan, the CEO of Ryan LLC and a major player in Texas politics, who gave $116,500 to PACs and party committees, said the donations were supposed to have been split between himself and his wife.

"Although these contributions are showing up in my name only, all of them ... were made by my wife and me from the joint account of Amanda and George B. Ryan and should have been attributed to both of us," Ryan said in an email. He said that he would notify the relevant committees to reattribute half of his contributions to his wife.

Kurt Wheeler, managing director of Clarus Ventures, explained that his $51,650 in contributions to candidates and $121,450 in contributions to PACs and parties should also have been recorded as joint contributions from his wife and him, and that he believed that under California's community property laws, it was not necessary for both his wife and him to sign the checks.

"California is a community property state and all contributions are joint contributions," Wheeler said in an email. "I am not knowingly above any of the limits."

So that recipients know to split the contributions between the two donors in their disclosure filings, the FEC requires that joint contributions either carry the signatures of both parties or bear one signature and come from a joint account bearing the names of both parties.

Similarly, Robert Klein II, the head of Klein Financial Corporation, said that part of the $167,350 in contributions to PACs and parties identified by HuffPost had been accidentally attributed to him and not to his wife by the recipient committees. He also stated that he and his 26-year-old son share the same name and rarely use their suffixes to differentiate themselves.

"We try not to use [our suffixes], but in this case it's not serving us well," Klein admitted.

The FEC warns that joint contributions are one of the main reasons that donors may accidentally violate the campaign finance limits. "If, however, you alone sign the check or note, the recipient committee must attribute the entire amount to you. That amount will count against your biennial limit," the FEC states.

Dr. Prem Reddy, the CEO of Prime Healthcare Services, who gave $100,300 to candidates, also appears to have been snared by this problem. A spokesman for Reddy said that contributions made to the Senate campaign committee of now-Secretary of State John Kerry were returned in 2013 and that the rest of the contributions came from a joint account and should have been split between Reddy and his wife.

"All of the campaign contributions to federal candidates in 2011-2012 were made through Prem Reddy, M.D.'s joint account with his wife, and were meant to be joint contributions," Fred Ortega, a spokesman for Reddy, said in an emailed statement. "We are in the process of contacting the individual candidate committees to reflect this in their reporting to the FEC."

A lawyer for Raymond Park said that the contributions listed by the FEC were "materially incorrect" and that a review of these contributions was in order.

Other donors who exceeded the overall limits, however, did not go over the line simply because their spouses failed to sign joint contribution checks or because campaign committees failed to file them properly.

John Canning, for one, gave so much that his contributions would have to be split among three people in order to stay under the overall limits. His wife, Rita Canning, also appears to have given above the overall limits, eliminating the possibility that their joint contributions were simply misfiled.

Both Donald Simms, the CEO of United Mining Company, and his wife, Susan Simms, also heavily exceeded the aggregate contribution limits. FEC records show that Donald Simms gave $102,300 to candidates and $127,400 to PACs and parties, and Susan Simms gave $91,300 to candidates and $123,300 to PACs and parties. The Simms did not return a request for comment.

Many other donors also gave vastly more than allowed, HuffPost found. Diversified Resources President Jeffrey Hurt gave $144,300 to candidates, more than three times the legal amount. Marie-Therese Tibbs gave $233,296 to PACs and parties, also more than three times the limit. David Wallace, president of Wallace Electrical Systems, and Thomas Cushman of Phillips Machine Service each donated more than two times the limit to candidates. None of these donors returned requests for comment; efforts to reach Marie-Therese Tibbs were unsuccessful.

IGNORANCE OF THE LAW

Many donors may have been unaware of the overall limits. When contacted about his excessive contributions, Raymond Park asked HuffPost, "Is that a law today?"

"I don't know of anything where I've given more than I should have, and if so I'd like to know about it," said John Roeser, chairman and founder of Otto Engineering, who gave $66,000 to candidates and $90,300 to PACs and parties. "Some of these things are arcane laws. It's hard to really not get caught up."

The overall contribution limits were enacted as part of the campaign finance regime created by Congress in 1974, after the Watergate scandal, and upheld by the Supreme Court in the 1976 Buckley v. Valeo decision. The limit on total contributions was originally $25,000 per donor per year. The 2002 McCain-Feingold reform law increased the overall limits and indexed them to inflation every two years.

Still, multiple donors contacted by HuffPost either didn't know about the limits or were confused by their application, especially with regard to joint contributions. The ever rising arms race for campaign funds and the tools used to raise more money may also have increased confusion among donors.

Many requests for campaign donations now come in the names of candidates, but ask for checks for joint fundraising committees . These committees allow candidates to simultaneously raise money for both their own campaigns and for the PACs and political parties of their choosing.

The joint fundraising committees are also designed to make contributing money easier for donors. Instead of writing multiple small checks to different candidates and groups, a donor can write a single large check to the fundraising committee -- as high or higher than $70,000 -- which the committee then splits among the participants in the joint fund on the donor's behalf.

For example, the Obama Victory Fund used by President Obama to raise money for his reelection campaign allowed donors to write checks up to $71,600. The money was then distributed among the Obama campaign, the Democratic National Committee and the federal accounts of eight swing-state party committees.

In the 2012 election, the most successful joint fundraising committees were Romney Victory, the Obama Victory Fund and Boehner for Speaker. All of these committees could receive contributions over $50,000 to be split among multiple recipients.

Giving to a joint fundraising committee can make it difficult, however, for even the most diligent donors to track where contributions are going and to make sure they are staying within the bounds of campaign finance law. Among the 48 donors that HuffPost identified as exceeding the PAC and party limits, 31 would have remained under the limits absent their joint fundraising committee contributions.

Dan Backer, head of DB Capitol Strategies, the law firm that brought the challenge to the overall contribution limit to be argued before the Supreme Court, said that the confusion over the contribution limits and the violations, even by those who are aware of the rules, are signs that the law should be invalidated.

"It just goes to show you that a law so complex and counter-intuitive that even with an attorney and a presumably sophisticated donor, it still gets accidentally breached, probably shouldnt be a law," Backer wrote in an email.

Campaign finance reformers disagree, arguing that a loosening of the limits will only make candidates and parties more reliant on the largest donors and allow candidates raising money through joint fundraising committees to solicit contributions from individual donors that could exceed $2 million -- exactly the kind of contributions the limit was put in place to prevent.

"This would take us back to a system of huge contributions that the Supreme Court in the past has indicated to be an inherently corrupt system," said Wertheimer of Democracy 21.

Adding to the problem is the fact that the FEC does not provide any oversight of the overall limit unless pressed to do so by a specific complaint from outside the commission.

"It's a classic example of the problems you can run into when you don't have enforcement of the campaign finance laws," Wertheimer said.

According to Campaign Legal Center lawyer Paul S. Ryan, the FEC can levy fines "equal to the amount of the contributions involved or up to twice that amount in the case of a knowing and willful violation." Donors who can show they exceeded the limit inadvertently are unlikely to face the full fine, or any fine at all.

The last major enforcement action for violating the overall limits came in 1990 after the Los Angeles Times found at least nine wealthy donors to be in excess of what was then a $25,000 annual limit. The FEC ultimately levied a total of $64,000 in fines against 10 donors.

Since then, the FEC has levied fines against fewer than 10 donors, all of whom reported themselves as having violated the limits. There have been no fines against any donor since the limits were increased under the 2002 McCain-Feingold law.

One of the primary reasons that the FEC usually ignores the overall limit is that there is no unique identifier -- a user ID -- required for donors to federal campaign committees. Donors can give under multiple names, use different addresses and list varying occupations and employers, making it very difficult for the agency to track one individual's donations.

"If you can imagine trying to aggregate one person across hundreds of -- thousands of -- committees with different spellings, addresses. It would be quite challenging to do that," FEC spokesman Christian Hilland said. "So currently the process is that anyone can file a complaint on the biennial limits, and from there it would go through the complaint process."

Wertheimer counters that the FEC has had ample time to address this enforcement hurdle. "This has been brought to the commission's attention in the past, whether through complaints that I've been involved in following or through media coverage," he said, "but they don't correct the problem."

Aaron Bycoffe contributed reporting.