Ambassador Gordon Sondland’s description of the pressure placed on US diplomats to sustain and advance President Trump’s effort to extract political favors from Ukraine has taken the impeachment inquiry into the embattled president to a new level: the John Dean level.

“Was there a ‘quid pro quo?’ As I testified previously, with regard to the requested White House call and White House meeting, the answer is ‘yes,’” Sondland told the House Intelligence Committee Wednesday.

The US Ambassador to the European Union, a key figure in the scandal who once tried to cover for Trump, provided dramatic and revealing testimony implicating the president—both in an extended opening statement to the House Intelligence Committee and in frank responses to questions from committee chair Adam Schiff and the lead counsel for committee Democrats, Daniel Goldman. Again and again, Sondland spoke of how decisions to scramble US foreign policy with regard to Ukraine were made to satisfy “the boss”: Donald Trump. Again and again, he said he was acting “at the express direction of the President of the United States” in efforts to secure a Ukrainian commitment to launch an investigation that Trump clearly hoped would embarrass a leading 2020 contender, former vice president Joe Biden. Again and again, he confirmed that he believed aid to Ukraine was conditioned on the announcement of investigations. Again and again, he described demands from Trump’s personal lawyer, Rudy Giuliani, that relations with Ukraine be bent to achieve domestic political ends as “expressing the desires of the president.”

Sondland provided damning testimony against the president he is currently serving, just as Dean, with his cooperation with the Watergate inquiry (before and after Nixon fired him), provided damning testimony against the president he served. The parallels were immediately noted, even before Sondland completed his opening statement during the extraordinary Wednesday morning session.

“This is a John Dean moment. It will live forever in American political history,” observed George Conway, the conservative lawyer and husband of White House aide Kellyanne Conway who has emerged as a stark critic of the president. Tony Schwartz, the business-book author who ghostwrote Trump: The Art of the Deal, said, “We are watching the John Dean of the Trump presidency.” MSNBC host and longtime legal commentator Ari Melber simply announced, “Holy cow Gordon Sondland [is] going full John Dean in [his] opening statement,” which, as Melber noted, confirmed descriptions of Trump’s actions as “‘quid pro quo’ bribery,” implicated Rudy Giuliani, showed Secretary of State Mike Pompeo was “in the loop,” and implicated Trump.

We can acknowledge that Donald Trump is not Richard Nixon and that the Ukraine scandal is different from Watergate. Yet there are reference points that matter. For instance, the Watergate inquiry reached a critical turning point when White House counsel Dean began to confirm the full extent of his boss’s wrongdoing. From the beginning of the current inquiry, there has been a question of whether someone with firsthand knowledge of Trump and Giuliani’s project would confirm the facts that might form the basis for a compelling article of impeachment based on Trump’s pressuring of Ukrainian President Volodymyr Zelensky to “do us a favor” by launching investigations into a domestic electoral rival.

Sondland has emerged as that figure. He is a controversial witness, who has moved from being a defender of the president to a threat, just as Dean did. For his part, Dean praised Sondland on Wednesday, saying, “It’s really nice to see someone putting country over party.” Now a commentator for CNN, Dean acknowledged during a break in Wednesday’s proceedings that “there are some parallels” between his circumstance and Sondland’s—recalling the refusal of the Nixon White House to release records that he needed, just as the Trump White House refused to release records Sondland has sought.

Schiff noted the current obstruction, as he did the deeper revelations from Wednesday morning. “We now see the veneer has been torn away,” the chairman announced during a break in the hearing. He correctly described Sondland’s testimony as “the most significant evidence to date [regarding] a basic quid pro quo.” Specifically, Schiff spoke of “the conditioning of official acts for something of great value—these political investigations. It goes right to the heart of the issue of bribery, as well as other potential high crimes or misdemeanors.”

That is clearly the case. The question, then, is no longer one of “if” but rather of “when” the House will write and act upon articles of impeachment. Sondland’s testimony has made the next stages in the impeachment process inevitable. And this is where Dean points to differences. He has argued that a changing media landscape has accelerated and altered political debates, going so far as to assert, “There’s more likelihood [Nixon] might have survived [Watergate] if there’d been a Fox News.” Dean has written and spoken at great length about the Republican Party’s reformation as a far more rigidly conservative and, in many instances, authoritarian party. He’s suggested that this makes GOP breaks with Trump less likely—noting, after observing this week’s hearings, that the approach of Intelligence Committee Republicans has made it “very clear” to him that “this is a whole new breed of impeachment inquiry.”

Yet Wednesday’s testimony was so devastating that a key member of the Intelligence Committee, Florida Democrat Val Demings, noted, “Ambassador Gordon Sondland just directly implicated President Trump.”

Deming repeated key lines from the ambassador’s testimony:

“At the express direction of the President…”

“I followed the directions of the President…”

“Based on the President’s direction…”

Then she asked the critical question: “Will my GOP colleagues remember their oaths and defend our democracy?”

That is the eternal question. It was asked in the Watergate era, after John Dean shredded the defenses Republicans had sought to mount for Richard Nixon. And it must be asked now that Gordon Sondland has shredded the defenses that Republicans are mounting for Donald Trump.