It seems like the Ukraine scandal keeps getting more and more complicated. There are questions over process, transcripts coming out and excuses by President Donald Trump s allies muddying the facts.

But in reality, it all remains very simple as simple as when the whistleblower complaint first came out. Making the entire scandal seem messy and complicated is exactly what Trump and his allies are aiming to do in advance of this weeks first House hearings in the impeachment investigation.

Here are the key facts:

Trump pressured a foreign country to investigate his political rival.

Trump manipulated U.S. foreign policy for his own political benefit. On July 25, Trump had a call with newly elected Ukrainian President Volodymyr Zelensky. According to a White House-released transcript , Trump said he wanted Ukraine to investigate two matters: first, whether Ukrainians were involved in the 2016 election hack of the Democratic National Committee, and second, Vice President Joe Biden s role in preventing an investigation into Burisma, a Ukrainian energy company whose board his son sat on.

Theres a lot of talk about Bidens son, that Biden stopped the prosecution and a lot of people want to find out about that so whatever you can do with the Attorney General would be great, Trump told Zelensky. Biden went around bragging that he stopped the prosecution so if you can look into it.

Both Trumps assertion about Biden and his claim that Ukraine interfered in the 2016 U.S. election are conspiracy theories.

Trump withheld U.S. military aid to Ukraine.

A week before Trump had his call with Zelensky, Trump told his chief of staff to hold back $400 million in military aid for Ukraine, which had been approved by Congress.

William Taylor, who was the top U.S. diplomat in Ukraine, confirmed to House lawmakers that Trump blocked the aid and refused to meet with Zelensky until he secured a promise that Ukraine would investigate the Bidens. Taylor took notes from his time in the position, backing up his account.

That was my clear understanding , security assistance money would not come until the president committed to pursue the investigation, Taylor said.

Trump ally Gordon Sondland, a donor who became U.S. ambassador to the European Union, also confirmed that he told a top Ukrainian official that the country would have to go along with Trumps demands to get the financial assistance. (Sondland, however, had initially told investigators that he never thought there was a precondition on the aid.)

Trump has insisted he withheld aid because he wanted Ukraine to more aggressively root out corruption.

Corruption is incredible in Ukraine, which bothered me a lot, Trump said this month. And it also bothered me very, very much that Germany, France and all of these other countries arent putting up money, but were always the sucker that does it.

But that claim doesnt stand up to scrutiny : Ukraine was already taking anti-corruption steps and European nations outpace the United States in spending on Ukraine.

The White House tried to cover up Trumps actions.

There were no sensitive national security secrets in Trumps call with Zelensky. But nevertheless, the White House moved the transcript of the call to a highly classified server, making it harder for other officials to access it and know what was said.

Army Lt. Col. Alexander Vindman, the top Ukraine adviser at the White House, had been listening to the July 25 call and was disturbed by what he heard. When he shared his concerns with White House lawyer John Eisenberg, Eisenberg proposed moving the transcript to the separate system. In other words, the focus was on hiding the evidence rather than confronting what had happened.

Its not clear what, if any, role Trump had in this cover-up.

Rudy Giuliani had an outsized role in foreign policy, despite not being in government.

A central figure in this scandal is Rudy Giuliani, Trumps personal lawyer. Giuliani does not work in the White House and has no government job. Yet he was running his own foreign policy operation, apparently with Trumps blessing, and pushing the Biden conspiracy theory.

John Bolton, then the national security adviser, reportedly called Giuliani a hand grenade and called the effort to pressure Ukraine for political purposes a drug deal.

In Trumps July 25 call with Zelensky, he repeatedly asked the Ukrainian president to work with Giuliani even though, again, Giuliani did not serve in government.

Two of Giulianis associates in his campaign to pressure Ukraine were indicted on federal campaign finance charges in October.

Giuliani was also a main driver in getting rid of Marie Yovanovitch, the U.S. ambassador to Ukraine, because she was seen as an obstacle to getting Ukraine to investigate the Bidens.

The whistleblower complaint remains correct and largely irrelevant.

Theres been a significant amount of speculation by Trumps conservative allies about the identity of the whistleblower, with some right-wing outlets trying to push the media to publish the name of the person they believe is the author of the bombshell memo.

But at this point, the memo and its author are almost irrelevant. The whistleblower admitted to hearing about the phone call and what happened from other White House officials but did not witness it. The complaint was meant to be a roadmap for Congress to pursue further investigation.

Other individuals with firsthand knowledge of the call have since confirmed what the whistleblower originally wrote.