There are two parts to the impeachment story: pre-Sondland testimony and post-Sondland testimony. The second will be more perilous to Donald Trump than the first and will include the Democratic majority in the House of Representatives voting to send an impeachment referral to the U.S. Senate—of that, we can now be certain. Looking further afield, a few other things also seem clear.

The House Republican caucus, which is much more comfortable acting as a raging protest group than a governing party, won’t abandon Trump. The White House’s narrative of a corrupt alliance of Democrats, deep-state officials, and the media conspiring to take down an anti-establishment President is one that appeals to the conspiratorial world view of many Republican representatives, who, in any case, are also beholden to Trump’s fanatical supporters and know it.

As an indication of what is to come, on Wednesday afternoon, Representative Steve Scalise, the House Republican Whip, tweeted out an exchange between Steve Castor, the G.O.P. staff counsel, and Sondland, a Trump donor turned Ambassador, in which Sondland conceded that Trump hadn’t personally told him about any preconditions for a White House meeting with Volodymyr Zelensky, the Ukrainian President, or for the release of hundreds of millions of dollars of U.S. aid to Ukraine. Jody Hice, the Republican congressman for Georgia’s Tenth District, quickly responded to Scalise’s tweet, writing, “The impeachment hoax continues to unravel, day by day, minute by minute. #DemsGotNothing.”

That’s an interesting way to describe testimony in which Sondland explicitly said that there was a quid pro quo and that every Ukraine-related action he took was ordered by the President, orchestrated by Rudy Giuliani, and sanctioned by a number of other top officials, including Vice-President Mike Pence, Secretary of State Mike Pompeo, and Mick Mulvaney, the acting White House chief of staff. It was notable that Republicans in the Senate, who ultimately will decide Trump’s fate, reacted more cautiously to Sondland’s testimony. Mitch McConnell, the Senate Majority Leader, told reporters that he wasn’t watching the hearing. Thom Tillis, the North Carolina senator who is up for reëlection next year, said something similar. It was left to Georgia’s David Perdue, a Trump loyalist who is also up for reëlection next November, to trumpet the White House line that the entire impeachment process is “nothing but a sham and a show trial.”

Even after Sondland’s testimony, the vast majority of Republican senators will probably line up with Perdue and Trump. Some of them subscribe to the deep-state theory. Others are intimidated by Trump’s Twitter feed, his crowds, and his media outriders, such as Laura Ingraham and Sean Hannity. All Republicans are aware of what happened to Bob Corker and Jeff Flake after they crossed Trump: they disappeared from public life. At least some Republican senators, however, will surely demand a more plausible narrative than the claim that the President can’t be guilty of anything simply because, in September, after an anonymous whistle-blower revealed his efforts to extort Zelensky, he agreed to meet with the Ukrainian President and release the U.S. aid.

This was essentially the argument that Jim Jordan, the Ohio brawler whom the Republicans drafted onto the Intelligence Committee to soften up the witnesses, put forward when he got to question Sondland. “They get the call, they get the meeting, they get the money,” Jordan said. “It’s not two plus two—it’s 0 for three.” Regardless of its value as a sound bite, this dismissive line won’t suffice for Republican senators facing tough reëlection contests, and there are quite a few of them apart from Tillis; Susan Collins, of Maine; Cory Gardner, of Colorado; Martha McSally, of Arizona; and Joni Ernst, of Iowa. On the subject of impeachment, all of these Republicans were conspicuously silent on Wednesday.

So what will the Republicans’ fallback position be post-Sondland? One possibility, which some conservative commentators floated on Wednesday, is to try to separate the quid pro quo for a Zelensky visit to the White House, which Sondland described in some detail, from the quid pro quo for the restoration of U.S. aid, which Sondland wasn’t in a position to observe up close, because it was arranged from within the White House. In reality, of course, these two things were part of the same effort by Trump and Giuliani to extort the new government in Kyiv. But if Trump’s defenders think they can even maintain the fiction that he didn’t put the aid on hold to pressure the Ukrainians to investigate the Bidens, they may be willing to concede, at least implicitly, that he denied Zelensky an Oval Office meeting for the purpose of demanding investigations into 2016 and Burisma, the Ukrainian company that employed Hunter Biden.

As a legal matter, the distinction between inviting a foreign leader to the Oval Office and providing U.S. aid isn’t very great: they are both items of value, which, in Adam Schiff’s case for the prosecution, Trump used to bribe Zelensky into providing him with dirt on a political opponent. In political terms, there could be a difference, though. The Democrats “know, as well as everybody knows, that nobody is impeaching a President of the United States over denying a visit to the White House,” Andrew McCarthy, a former federal prosecutor who writes for National Review, said on Fox News.

When the impeachment referral reaches the Senate, much could revolve around legal arguments about what bribery means in the context of impeachment. Ultimately, however, this is a political process, and the Democrats, too, have some tricky calls to make as they seek to press the advantage that the first four days of hearings have given them. In particular, they have to decide whether to stick to the accelerated schedule that Nancy Pelosi and Schiff have laid down, which, according to some accounts, could lead to an impeachment referral as early as next month. Or should they slow down a bit and go to the courts to try to obtain some of the official documents that Sondland said he was denied access to, and also to obtain the testimony of some of the officials that he named, particularly Pompeo and John Bolton, the former national-security adviser?

So far, the Democrats have largely restricted themselves to taking the testimony of people who are willing to testify, which has illuminated a conspiracy to abuse Presidential power that now looks as bad or worse than the Watergate burglary. The guess here, which was backed up on Wednesday evening by some reporting from Politico, is that the Democrats won’t change course now, and neither will the Republicans. But, after Sondland’s testimony, one side has a lot more reason to be concerned.