President Donald J. Trump was impeached on Thursday.

I know that he was technically impeached when the House voted to do so in December. But the truth is, as a political and historical matter, Thursday was the day. House Speaker Nancy Pelosi’s strategy—brilliant to fans, incomprehensible to foes—of sitting on the articles of impeachment left a lot of people wondering whether this show was ever going to get on the road.

Now, with the chief justice of the Supreme Court sworn in to preside over the Senate trial, and senators sworn in as jurors, there’s no mistaking that it’s about to go down. The clearest sign that the Senate is taking this at least somewhat seriously: Senators are handing over their cellphones before they enter the chamber. That’s not good news for the president.

Oh, it’s still unlikely there will be enough votes to remove Trump from office. But having talked with many GOP senators since the Ukraine story broke, I can tell you that few have paid close attention to the facts of the case. Some weren’t engaged because they wanted—or said they wanted—to avoid reaching conclusions since they would have to be impartial jurors. Others seemed to think, understandably, that the Ukraine drama was simply the latest chapter in the long-running story of the media and Democrats rushing to “get” Trump no matter what. Others appeared eager to stay in their lanes, avoid the cable-news shout shows and get on with the jobs they were sent to Washington to do.

Whatever the reasons, I’ve been shocked at how so many senators didn’t know—or claimed not to know—many of the central facts from the House hearings and news reports.

That’s over.

Now, they all have to sit in a room like good boys and girls and stay absolutely quiet as the House impeachment managers make their case. They can’t play Candy Crush or check out the latest sports scores on their phones. The rules say that if they even talk among themselves, they can be imprisoned.

Some senators have said they want to be protected from learning relevant new facts, claiming that because the impeachment process in the House was flawed and rushed—which is true—the Senate shouldn’t be obligated to do the heavy lifting of evidence-gathering. Though few have been as adamantly opposed to hearing new evidence as Sen. Lindsey Graham (R-S.C.).

On Wednesday, Sen. Susan Collins (R-Maine) ignited a furor when she asked why new evidence provided by Lev Parnas—a Ukrainian grifter who’d been working closely with Trump’s personal fixer, Rudy Giuliani—wasn’t in the report sent by the House. When a journalist pointed out that the evidence had just surfaced, Collins replied, “Well, doesn’t that suggest that the House did an incomplete job then?”

Maybe this was a sign she wasn’t paying attention or an indication she doesn’t want to hear new evidence. If it’s the latter, she has a point. If representatives had taken time to do all of their due diligence, they likely would have uncovered more evidence, whether from Parnas or other potential witnesses.

But, looked at from a broader perspective, so what? Republicans screamed “show trial” during the House hearings. It was an overheated and indefensible claim. But if you’re on record saying you’re opposed to show trials—i.e., proceedings in which relevant evidence is ignored in pursuit of a foreordained conclusion—then saying you don’t want all of the facts is terribly hypocritical.

People are going to watch the hearings. They’re going to see miserable senators presented with ample evidence that the president used his office to pressure the Ukrainians to sully a political opponent. If the only times Republican senators make a fuss are when they maneuver to avoid hearing even more damning evidence, or demand that the Senate participate in the president’s strategy of making Joe Biden the issue, they won’t merely be violating their oaths to deliver impartial justice; they will risk going down in history—and appearing to voters—as participants in a cover-up.

Some senators will be fine with that, because that’s what a majority of their voters want. For those who either come from states that don’t have enough Trump base voters to get re-elected or are burdened with a politically inconvenient concern about their reputations, it will be a real problem. The one thing none of them will be able to claim, however, is that they don’t know the facts because they weren’t paying attention.

Photograph of Mitch McConnell by Mark Wilson/Getty Images.