On Tuesday, Bill Taylor, the acting U.S. ambassador to Ukraine, told Congress about President Donald Trump’s extortion campaign against that country. Taylor testified that Trump used two weapons—a proposed White House meeting with Ukraine’s president, and the threat of withdrawing military aid—to press Ukraine to investigate Trump’s Democratic opponents. But Taylor’s testimony establishes more than a quid pro quo. It destroys Republican excuses for the president’s behavior, and it details the administration’s maneuvers to cover up what he did.

Here are Taylor’s key revelations.

The first quid pro quo: a meeting. Text messages between Taylor and his colleagues, released on Oct. 3, document the administration’s efforts to extract—through the offer of a meeting between Trump and Ukrainian President Volodymyr Zelensky—a pledge by Ukraine to pursue two investigations that would help Trump. One investigation would look into the debunked idea that Ukraine colluded with Democrats in 2016 and somehow framed Russia for hacking the Democratic National Committee. The other investigation would target Burisma, a company whose board once included Hunter Biden, the son of former Vice President Joe Biden.

Taylor’s testimony, detailed in a 15-page chronology, confirms that this was a quid pro quo. He describes a July 19 phone call in which two officials—Alex Vindman, the National Security Council’s director of European Affairs, and Fiona Hill, who was then the NSC’s senior director for European and Russian Affairs—recounted a July 10 meeting at the White House. In that meeting, Gordon Sondland, the U.S. ambassador to the European Union, “connected ‘investigations’ with an Oval Office meeting for President Zelenskyy.” Taylor reports that several weeks later, in a Sept. 1 phone call, Sondland “told me that President Trump had told him that he wants President Zelenskyy to state publicly that Ukraine will investigate Burisma and alleged Ukrainian interference in the 2016 U.S. election.” In this call, according to Taylor, Sondland confirmed that he had told Ukrainian officials “a White House meeting with President Zelenskyy was dependent on a public announcement of investigations.”

That’s three conversations in which the proposed deal with Ukraine was openly specified.

The second quid pro quo: military aid. On Sept. 1, Hill’s successor at the NSC, Tim Morrison, told Taylor about a conversation Sondland had that day with Andriy Yermak, a top aide to Zelensky. According to Morrison’s account, as relayed by Taylor, Sondland “told Mr. Yermak that the security assistance money would not come until President Zelenskyy committed to pursue the Burisma investigation.” Taylor says that in a phone call later that day, Sondland said Trump “told him that he wants President Zelenskyy to state publicly that Ukraine will investigate Burisma and alleged Ukrainian interference in the 2016 U.S. election.” According to Taylor, Sondland also told him that U.S. “security assistance” was “dependent on a public announcement of investigations.”

That’s three conversations in which the proposed deal with Ukraine was openly specified. And Trump kept repeating the terms. Taylor says that on Sept. 7, Morrison “described a phone conversation earlier that day between Ambassador Sondland and President Trump” in which Trump “insist[ed] that President Zelenskyy go to a microphone and say he is opening investigations of Biden and 2016 election interference.” The next day, Sondland told Taylor that “he had talked to President Trump” and that Trump “was adamant that President Zelenskyy, himself, had to ‘clear things up and do it in public.’ ” Trump denied that this was a quid pro quo, but he told Sondland that if Zelensky “did not ‘clear things up’ in public, we would be at a ‘stalemate.’ ”

The clearest expression of the quid pro quo is a metaphor that was used by Trump’s accomplices. Taylor says that on Sept. 8, Sondland “tried to explain to me that President Trump is a businessman. When a businessman is about to sign a check to someone who owes him something, he said, the businessman asks that person to pay up before signing the check.” According to Taylor, former special envoy to Ukraine Kurt Volker “used the same terms several days later while we were together at the Yalta European Strategy Conference.” During this time, Trump was literally withholding a check from Ukraine: military aid appropriated by Congress.

The demand for a public statement. Trump’s defenders argue that when he pressed Zelensky to investigate Biden and other Democrats, he was seeking truth and justice, not political ammunition. Taylor’s evidence dispels that nonsense. In the Sept. 1 conversation, Sondland said Trump made clear that he wanted Zelensky to “state publicly” that Ukraine would investigate Burisma. In the Sept. 7 conversation, Morrison confirmed that Trump insisted that Zelensky “go to a microphone and say” he was launching investigations of Biden and the Democrats. In the Sept. 8 conversation, Sondland again said Trump was adamant that Zelensky issue such a statement “in public.” If Trump had cared about truth or justice, a private commitment to look at the facts would have sufficed. But to smear Biden and the Democrats, Trump needed a public announcement.

The sneaking. While demanding a public statement from Ukraine, Trump and his operatives tried to keep these demands secret. Taylor’s testimony explains this paradox. On Aug. 16, he learned that Yermak “had asked that the United States submit an official request for an investigation into Burisma’s alleged violations of Ukrainian law, if that is what the United States desired.” This was a shrewd move by Yermak. It protected Ukraine from accusations of interfering in the 2020 election, and it challenged the Trump administration to take responsibility, in public, for enlisting Ukraine’s help. A formal request would have spoiled any scheme by Trump to make it look as though Ukraine was spontaneously incriminating Biden and the Democrats. So the administration never submitted such a request. Instead, it tried to squeeze Ukraine behind the scenes.

Taylor says that in response to Yermak’s talk of an official request, he gave Volker “the name of a Deputy Assistant Attorney General whom I thought would be the proper point of contact for seeking a U.S. referral for a foreign investigation.” There’s no evidence that this lead was pursued. Two weeks later, Sondland and Taylor discussed whether Ukraine could deliver a statement about investigations “in coordination with Attorney General [Bill] Barr’s probe into the investigation of interference in the 2016 elections.” Again, there’s no sign of any follow-up. The point of coercing Ukraine was to bypass American standards of justice and extract a smear job.

The “corruption” lie. Republicans claim that when Trump pressed Ukraine for investigations, his goal was to root out corruption. The reconstructed transcript of his July 25 phone call with Zelensky refutes that explanation. It proves that Trump pressed for two specific investigations—Biden and 2016—and named no other potential investigations. The text messages between Sondland, Volker, and Taylor show the same pattern.

Taylor’s chronology further demolishes this “corruption” defense. He notes that during Zelensky’s first two months in office, the president “appointed reformist ministers and supported long-stalled anti-corruption legislation.” Zelensky also opened an anti-corruption court and stripped lawmakers of their immunity to prosecution. Yet Trump continued to insist that Ukraine was corrupt. Why? Because “corruption,” to him, was just a code word for Ukraine’s failure to investigate Democrats.

What the lawyers knew. Now that Trump’s extortion of Zelensky has been exposed, some Republicans want to pin it on Trump’s personal lawyer Rudy Giuliani. They think it can be dismissed as a rogue operation. But Taylor reports that White House lawyers were repeatedly told what was going on. After the July 10 meeting at which Sondland outlined the meeting-for-investigations quid pro quo, then–national security adviser John Bolton instructed Hill to “brief the lawyers” about Sondland’s disclosure. Two months later, Morrison told Taylor that he had informed “the NSC lawyers” about Trump’s demand for investigations of the Democrats. This adds to a pile of evidence that officials all the way up to Trump’s acting chief of staff, Mick Mulvaney, were aware of the scheme.

The cover-up. The Sondland-Volker-Taylor text messages, like the whistleblower complaint that first exposed the extortion operation, show multiple attempts to hide this operation from the public. Taylor’s testimony adds several other incidents. On June 28, according to Taylor, Sondland proposed to exclude “regular interagency participants” from a call with Zelensky. Sondland said he “wanted to make sure no one was transcribing or monitoring” the call. On July 19, Taylor learned that Volker had met with Giuliani to discuss Ukraine. When Taylor asked Volker about the meeting, he got no response. After the July 25 Trump-Zelensky phone call, Taylor never got a readout of the call, even though he was supposed to represent the United States in Ukraine. Bolton, Taylor, and other opponents of the conspiracy were being shut out.

Trump and his surrogates will try to discredit Taylor. Unfortunately for them, Taylor preserved records and documented in real time what he witnessed. At various points in the chronology, he wrote memos for the record or reported his conversations to colleagues who could later back him up. He’s well armed, alongside other witnesses, to expose the Ukraine conspiracy—and to take down everyone in the administration who knew about it.