Acting United States Ambassador William Taylor testified in front of impeachment investigators on Tuesday, and if his allegations are indeed true, President Trump's back channel to Ukraine did attempt to make a deal. The deal was that, in order for his administration to provide congressionally approved funding for Ukraine, Ukraine would have to reciprocate by launching an investigation into Hunter Biden and the Burisma energy company where he had a very lucrative sinecure.

In other words, our ambassador to Ukraine just said that Trump used the powers of the presidency for personal political gain. In Latin, we refer to this as a quid pro quo.

Taylor, a career diplomat who has served in Republican and Democratic administrations alike, claims in the month after he first arrived in Kyiv in the summer, the purpose of the "irregular" and secondary back channel of U.S. communications with Ukraine, spearheaded by then-Special Envoy Kurt Volker, Ambassador Gordon Sondland, Energy Secretary Rick Perry, and Rudy Giuliani, "diverged" from the official channel of communications.

At the end of June, and per Trump's request, Sondland arranged a phone call between Ukraine and the back channel, sans Giuliani, who Taylor didn't know was involved in Trump's diplomacy at the time. Sondland explicitly told Taylor that he didn't want to include "regular interagency participants" on the call. The recently elected Ukrainian President Volodymyr Zelensky was eager to meet Trump but wanted to do so by mid-July, Taylor claims he realized that "the meeting President Zelensky wanted was conditioned on the investigations of Burisma and alleged Ukrainian interference in the 2016 U.S. elections. It was also clear that this condition was driven by the irregular policy channel I had come to understand was guided by Mr. Guiliani."

During a National Security Council call at this time, an Office of Management and Budget staffer told Taylor directly that Trump had ordered a hold on funding to Ukraine. While the cause was still unclear to Taylor, he said, "The irregular policy channel was running contrary to the goals of longstanding U.S. policy."

"Ambassador Bolton, in the regular Ukraine policy decision-making channel, wanted to talk about security, energy, and reform," Taylor testified. "Ambassador Sondland, a participant in the irregular channel, wanted to talk about the connection between a White House meeting and Ukrainian investigations."

Trump's defenders have pointed out that even if his intentions were corrupt, the Ukrainians claim that they knew of no quid pro quo. That would theoretically render the corruption moot — you can't extort someone unless they know about it.

But Taylor testifies that Ukrainian official Oleksandr Danyliuk told him that Zelensky "did not want to be used as a pawn in a U.S. re-elections campaign." And the Ukrainian president himself knew that enough of an indelicate tit-for-tat was occurring that he complained about it to a top American official.

Despite Taylor's demand that the U.S. stay clear of a request "to conduct an investigation based on violations of their own [Ukrainian] law" with regards to Burisma and the Bidens, he ultimately discovers Trump's end goal from Sondland: "he wants President Zelensky to state publicly that Ukraine will investigate Burisma and alleged Ukrainian interference in the 2016 U.S. election."

"Ambassador Sondland said, 'everything' was dependent on such an announcement, including security assistance," Taylor testifies. "He said that President Trump wanted President Zelensky 'in a public box' by making a public statement about ordering such investigation."

That's not all. According to Taylor, Secretary of State Mike Pompeo, CIA Director Gina Haspel, then-national security adviser John Bolton, and Defense Secretary Mark Esper all knew about Trump's hold and sought to schedule a meeting to convince Trump to release the funds. And yet, the administration held on until the very last minute, putting a pivotal ally in a position where they could have reacted to the threat of losing a significant amount of funding while fighting the immediate foe of Russia.

Trump was willing to threaten that ally and, thus, the interests of the people he was elected to protect and serve. Moreover, he did so for his own personal political gain.

"Ambassador Sondland tried to explain to me that President Trump is a businessman," Taylor testified. "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."

So there was a quid pro quo. There was an abuse of office. And now there will be an impeachment inquiry.