The barricade of GOP resistance to any kind of meaningful oversight of Donald Trump appeared to be cracking Tuesday night.

Arizona Sen. John McCain, always good for a quote, spoke at a dinner for the International Republican Institute and straightforwardly compared the onrushing nexus of obstruction of justice charges to Watergate.

@SenJohnMcCain at IRI dinner now- "We've seen this movie before. It's reaching Watergate size and scale....This is not good for the country" — Ana Navarro (@ananavarro) May 17, 2017

Jason Chaffetz, the finger-in-the-wind chair of the House Oversight Committee, has requested all of former FBI Director James Comey’s records detailing interactions with the president. Cathy McMorris Rodgers from the House GOP leadership backed Chaffetz’s letter, and so, later, did Speaker Paul Ryan.

It’s an extremely modest move, under the circumstances, but as Jonathan Chait writes, it’s a significant one: “The policy of shutting down all oversight or investigation is no longer tenable.” And once Republicans start tugging on the string, it’s not clear they can stop the whole sweater from unraveling.

James Comey has the receipts

The news that Trump leaked classified information to the Russians was the start of the story. The details — that it was Israeli intelligence, that the US did not have permission to share it with third parties (especially close allies of Iran), and that it could endanger the life of a valuable Israeli operative — are about as bad as they could possibly be from a political perspective.

NEW: Pres. Trump's disclosure endangered spy placed inside ISIS by Israel, current and former U.S. officials say. https://t.co/5scDLqA6Ot — ABC News (@ABC) May 16, 2017

But the real problem is Comey.

Not only is firing the FBI director to try to quash an investigation a textbook impeachable offense, it’s also simply political malpractice to pick a fight with a well-regarded FBI director. Lyndon Johnson considered firing J. Edgar Hoover, only to famously tell aides, “It’s better to have him inside the tent pissing out than outside the tent pissing in.”

As former Obama-era Justice Department spokesperson Matthew Miller warned soon after Trump fired Comey, the former FBI director is in the habit of keeping meticulous records of sketchy situations precisely in order to protect himself.

One thing I learned at DOJ about Comey: he leaves a protective paper trail whenever he deems something inappropriate happened. Stay tuned. https://t.co/sENlYyhL5B — Matthew Miller (@matthewamiller) May 12, 2017

In the initial rush of controversy last week, Republicans seemed to think Trump could pull this off. But the Tuesday afternoon story about Comey’s memo detailing Trump’s efforts to get the FBI to back off an investigation of former National Security Adviser Michael Flynn was a reminder that he can’t.

Whatever Comey knows is going to come to light. And if you’re a Republican who hasn’t been obstructing justice, it makes a lot more sense to have it come to light with you leading the charge for oversight than for everything to drip-drip-drip out into the newspapers.

With Comey outside the tent, the strategy of massive resistance is untenable.

Republicans used to be skeptical of Trump

The irony of this is that last summer and fall, plenty of Republicans were genuinely skeptical of Trump and at pains to distance themselves from him.

Ted Cruz famously urged Republican National Convention attendees to “vote your conscience.” Many leading members of the party didn’t attend at all. Susan Collins, Jeff Flake, Cory Gardner, Dean Heller, Mike Lee, John McCain, Lisa Murkowski, Rob Portman, Ben Sasse, and Dan Sullivan all said they weren’t going to vote for Trump — as did Kelly Ayotte and Mark Kirk, who ended up not surviving the election. A staggering 31 members of the House GOP caucus declined to endorse him.

Ryan, who did endorse Trump and never recanted it, nonetheless famously proclaimed at one point that he would no longer “defend or campaign with” him.

None of the various factors that made Trump unfit for high office vanished on Election Day. But Republican elected officials’ skepticism of him did. Suddenly it was no problem if he wanted to tap a crony with little public record as Treasury secretary or install a member of Russia’s Order of Friendship at the State Department. No effort was made to force him to divest from his businesses or put any kind of serious conflict of interest policy in place. His wildly unqualified son-in-law was installed as a top White House aide, and everyone just pretended it was fine.

Congress needs to see the Comey memo. — Jeff Flake (@JeffFlake) May 17, 2017

But it wasn’t fine. Indeed, the whole idea that it was fine amounted to little more than a vague hope that Trump would change, when of course he has not.

It’s not clear that Trump can survive scrutiny

I, of course, have no idea whether a thorough investigation will reveal some form of “collusion” between the Trump campaign and the Russian government. It does seem very likely that Flynn, at a minimum, broke a bunch of rules regarding monetary payments by foreign governments. And Paul Manafort sure seems to be in hot water regarding money laundering.

But even if all that turns out to have nothing to do with Trump, it seems highly questionable whether he can survive any kind of sustained scrutiny.

He’s not a squeaky clean guy who’s stumbled into scandal on this one Russia thing. He’s a president who has totally unprecedented — and clearly ongoing — financial conflicts of interest that allow parties with interests before the federal government to make cash payments more or less directly to the president of the United States. His daughter and son-in-law have related, but distinct, conflicts of interest. He’s been acting squirrelly for years about his tax returns, and has himself been repeatedly in business with people involved with money laundering and various other aspects of organized crime (Russian mafia, traditional mafia).

Besides which, even at their most scandal-plagued points, Richard Nixon or Bill Clinton could fall back on deep knowledge of American politics and public policy that Trump lacks. By contrast, as Ross Douthat writes, if you “read the things that these people, members of his inner circle, his personally selected appointees, say daily through anonymous quotations to the press,” it’s clear that “they have no respect for him, indeed they seem to palpate with contempt for him, and to regard their mission as equivalent to being stewards for a syphilitic emperor.”

Congress needs to do its job

The modest stirrings of conscience among congressional Republicans, though welcome, are also fairly tiny. Democrats, meanwhile, are already talking about impeachment.

It may well come to that, but if it does, it will take a long time.

In the interim, what the country really needs is a Congress that steps up and does its job. It is well within the institutional capacity of the United States Congress to begin to start trying to restructure the relationship of the Trump family to the American government in a proper way.

They can force real financial disclosure and meaningful separation between the Trump businesses and the Trump administration. They can insist that Trump install a real chief of staff — someone with governing experience — and empower him or her (rather than immediate family members) to serve as the actual head of staff. They can cough up the names of well-qualified people to serve in sub-Cabinet roles and insist that Trump put them forward.

To do so, they would have to give up the dream of a blitzkrieg attack on the social welfare state in favor of a lot of arduous, diligent work to simply put the institutions of state back together. And for now there’s no sign that either Ryan or Majority Leader Mitch McConnell is willing to take that step. But at this point, even congressional Republicans can’t really deny that there’s something wrong with the president of the United States.

The question is when they are going to start doing something about it.