Watergate had the White House tape capturing President Richard M. Nixon’s abuse of power, and it had John Dean, the truth-teller from the inside. In the Trump impeachment inquiry, we have the blow-by-blow evidence of a quid pro quo presented by this case’s truth-teller, career diplomat William B. Taylor Jr.

Not only did Taylor learn from a National Security Council aide that President Trump was holding up military assistance to Ukraine until Ukrainian President Volodymyr Zelensky publicly committed to investigating former vice president Joe Biden, but Taylor got the same message from Ambassador to the European Union Gordon Sondland. The detailed account in Taylor’s opening statement suggests he either has a very, very good memory or took some contemporaneous notes.

While Trump apologists have cooked up all sorts of excuses and conditions — e.g. they want evidence other than the July 25 call plus evidence that the quid pro quo was communicated to Ukraine — Taylor seems to have satisfied these conditions. The NSC aide told Taylor that Sondland had communicated the quid pro quo to Andriy Yermak, a Ukrainian official. And as if that were not enough, Sondland told Taylor directly “President Trump wanted President Zelenskyy ‘in a public box’ by making a public statement” and that “everything” (i.e. aid) was dependent on such an announcement. (Zelenskyy is how Taylor spelled the name in his remarks; in Ukraine, it’s the preferred spelling of the president’s name.)

Taylor’s testimony also means trouble for outgoing Energy Secretary Rick Perry, whom Taylor tags as a witness to this quid pro quo that Sondland intended to lay down. It’s also trouble for the Justice Department, which couldn’t manage to find anything wrong with this set of facts when a criminal referral was made, and which advised the acting director of national intelligence that he could not turn over the whistleblower complaint to Congress, as required by law.

For Republican toadies such as Sen. Lindsey O. Graham (R-S.C.), who have come up with one preposterous excuse after another to discount evidence of impeachable conduct, Taylor’s testimony and the other witnesses he identifies pose a real problem. (Graham just this past weekend insisted, “If you could show me that, you know, Trump actually was engaging in a quid pro quo, outside the phone call, that would be very disturbing.” Is this enough, senator?)

Goodness knows what excuses Republicans will come up with next, but we know now there is substantial evidence of the worst-case scenario: An American president tried to extort a foreign government into injecting itself into our election by finding dirt on a political opponent, using as leverage essential aid to an ally fighting against Russian aggression. That is what Republicans are being asked to defend.

Taylor’s testimony is significant for several reasons.

First, Taylor identified even more witnesses — e.g. Perry, NSC aide Tim Morrison — who can substantiate eye-popping and entirely credible evidence that Trump abused his power.

Second, the misconduct is unlike any other offenses in the Trump administration or in any other administration. This is far worse than Watergate, since the president acted in ways contrary to the national interest to help his political ambitions. Trump extorted an ally that we are supposed to be defending from Russian aggression in order to obtain illegal help in getting him reelected. Trump put his own interests (dirt on Biden) above American democracy and above our national security needs, which entail resisting Russian aggression in Europe. No other president has ever betrayed our democracy and our interests so brazenly.

Third, in recognizing the extraordinary nature of the misconduct and the evidence presented, Democrats remove the whistleblower from the equation (that person is irrelevant now that we have Taylor and others), strengthen House Speaker Nancy Pelosi’s determination to keep the impeachment investigation tightly focused on Ukraine (nothing else Trump has done is as remotely serious) and do damage to the “inappropriate but not impeachable” defense that Republicans have bandied about.

If we have not reached a tipping point for Senate Republicans to stop defending Trump’s high crimes and misdemeanors, we surely have reached the point at which we know whether there is any high crime and misdemeanor that would compel a significant number of Republicans to uphold their constitutional obligation. There won’t be many, but I would hope that a few would finally step forward.

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