The day Donald Trump took office, I wrote a column arguing that what was new and frightening here was that he had no reverence for the civic and governmental institutions of this country. This had never been true of a president before, at least in the modern era. George W. Bush’s administration twisted facts to get their war in Iraq. But even Dick Cheney understood that it had to appear as if everything was above board, as if the intelligence agencies were arriving at their conclusions independently.

Trump and the people advising him just don’t care. He is interested in our institutions only insofar as they can be used to help Trump. And the flip side was on display this weekend in his reckless Saturday morning tweets about Barack Obama. He’ll say anything about anyone without giving the slightest thought to how those words might damage these institutions and demoralize the people within them.

Because not only did he accuse Obama of something terrible and illegal, with no evidence to support the charge, but he also accused the law-enforcement and intelligence communities of colluding with the outgoing president to do something obviously illegal. Only a person with no respect for any of those institutions could make such a charge.

But it’s time now to focus not only on Trump and his psyche (although just quickly, before I turn away from that topic, I have to note that the most plausible theory I heard all weekend about why Trump did what he did was the hypothesis that he was miffed that the Obamas got that joint $65 million book advance; that’s just so Trump in every way).

But let’s talk about the Republicans.

When will they stand up to this guy? With one lone exception that I saw, most Republicans’ responses over the weekend were pathetically weak. Let’s start with this especially lame one, from Arkansas Senator Tom Cotton. After saying he knew of no evidence to support Trump’s claim, it must have struck him that someone in the White House might get mad at him, because he added: “It doesn’t mean that none of these things have happened, just means I haven’t seen them yet.” Ah. Thanks for that, Tom.

Others sounded less pliant but substantively were little better. Lindsey Graham has built up a lot of cred in this department, and understandably so, because he’s been a pretty tough Trump critic at times. But this, at a town hall over the weekend, where he obviously didn’t want to face a chorus of catcalls, was from weaseltown: “I’m very worried that our president is suggesting the former president has done something illegal. I’d be very worried if in fact the Obama administration was able to obtain a warrant lawfully about Trump campaign activity with foreign governments. It’s my job as United States senator to get to the bottom of this.”

No, it’s your job to say that unless he has evidence that he is ready adduce yesterday, a president of the United States has no business saying anything like this.

And here’s erstwhile stand-up comic Marco Rubio: “I’ve never heard that before. And I have no evidence or no one’s ever presented anything to me that indicates anything like that… But again, the president put that out there, and now the White House will have to answer as to exactly what he was referring to.”

The lamest of all was House Intelligence Committee Chairman Devin Nunes, who vowed to look into Trump’s claims. Yes, this is the same Devin Nunes who said recently that his committee will not look into any claims that Trump may have spoken with former National Security Adviser Mike Flynn about the latter’s contacts with Russia. Likewise, House Oversight Committee Chairman Jason Chaffetz said that while he’d seen no evidence to support Trump’s claim (that’s the part of his comments that was more widely picked up), he also added that his committee would take a “hard look” at Trump’s allegations.

The only statement by a Republican that was even somewhat informed by principle was the one issued by Nebraska Senator Ben Sasse. He used far sharper rhetoric than any of his colleagues to put the onus on Trump to deliver some proof: “The president today made some very serious allegations, and the informed citizens that a republic requires deserve more attention.” He demanded that if there was a court order authorizing a wiretap of Trump, the president obtain and copy of it and show it to the public or at least to the Senate.

Sasse is getting plaudits for saying what he said, and yes, comparatively speaking, he was a veritable Cincinnatus here. But it’s pretty pathetic that his statement stood out. What Trump did here was unbelievable. What will he say next about somebody, on the basis of no evidence? Obama is a former president who has millions of people who adore him and will have his back. But what will happen when Trump—the president of the United States, the most powerful man in the world—says something unsubstantiated about a judge, or a civil-liberties or immigration lawyer, or a journalist, or who knows, any citizen who gets on his bad side?

This is what despots do. In the olden days, when a despot said X committed a crime, poor X was usually led away to the stockade. That can’t happen here today. We think. Or can it? If Republicans don’t take a stand—not in defense of Obama, but in defense of our civic institutions and norms—we may yet find out.