Massachusetts Sen. Elizabeth Warren began her campaign with a challenge to the other Democratic presidential candidates : No super PACs, and no self-funding.

Now, as she firmly ensconces herself in the top tier of 2020 candidates, shes issuing another challenge: Every other Democratic presidential candidate should reveal the names of any donor or fundraiser who has a title with the campaign, and should report the date, location and host committee of any event they hold to raise funds. She also proposes making such disclosure mandatory if she becomes president.

If Democratic candidates for president want to spend their time hobnobbing with the rich and powerful, it is currently legal for them to do so but they shouldnt be handing out secret titles and honors to rich donors, Warren wrote in a Medium post Tuesday announcing her new campaign finance policy. Voters have a right to know who is buying access and recognition and how much it costs.

Warren has long made the corrupting influence of money in politics a signature issue. Her new proposal is meant to serve as both a contrast with top rival Joe Biden , who has relied on ties to wealthy donors to fund his campaign war chest, and as preparation for the general election, where Warren hopes to showcase her support for good government measures against President Donald Trump s corruption. Its also another signal Warrens top priority as president would be changing Washingtons internal rules in ways that make progressive successes more likely.

Our democracy shouldnt be bought and paid for by the wealthy and powerful. It belongs to all of us. When we use our voices and our votes, we can make real change big, structural change, Warren wrote on Medium. Thats why getting big money out of politics and addressing corruption in Washington are so important. These reforms make it possible to do everything else we need to do from addressing climate change to forgiving student loans.

Warren is also proposing a sharp limits on corporate PACs, making it more difficult to set up super PACs dedicated to a single candidate, banning lobbyists from donating to or fundraising for any candidate, significantly reforming the Federal Election Commission, lowering the maximum donation to a federal candidate or committee, and establishing a publicly financed matching program for small donations.