And yet millions of Americans fervently believe these things. Different polls find different things, and it’s always difficult to distinguish what people really believe from what they say on surveys. But if 30 percent of America’s 200 million registered voters are Republicans, and 40 percent of those don’t believe Obama was born in the US, well, that’s 24 million people, among them the most active participants in Republican politics.

In short, an increasingly large chunk of Americans believes a whole bunch of crazy things, and it is warping our politics.

This basic story has been told plenty of times (my longer version is here), but the reason we should not let it out of our sights right now is the Mueller investigation.

In short, what if Mueller proves the case and it’s not enough? What if there is no longer any evidentiary standard that could overcome the influence of right-wing media?

For Mueller’s findings to have any effect, they will have to break some part of the basic dynamic on the right. Here’s how it works:

Pundits and yellers in right-wing media compete to freak out the base and reinforce its allegiance to Donald Trump. The base leans on politicians. And most elected GOP officials are in seats safe enough that they fear a primary challenge from the base more than a Democratic challenger. The only way to stave off a primary is to pay obeisance.

That’s why Jeff Flake and Bob Corker are leaving the Senate. They no longer have any control over what their constituents believe or want, and their constituents believe and want increasingly ugly things. Sen. John McCain is saying all the right things now, but back when he faced his own Tea Party challenger, he sprinted right as fast as he could.

GOP politicians cannot (or feel that they cannot) cross the base. And the base is currently being lied to about the Mueller investigation at a furious pace. The entire right-wing machine has kicked into high gear, led by the president himself, furiously throwing out chaff about Comey, Mueller, Obama, Hillary, the dossier, the uranium, the emails, and whatever else.

As always, the goal of this media/political offensive (there is no longer much distinction) is less to present some coherent alternative account of the facts than to fill the atmosphere with fog, to give those on the right enough cover to slough off the charges as yet another liberal plot. (See Vox’s Sean Illing’s great interview with Charlie Sykes, the conservative talk-radio host who criticized Trump and was excommunicated, for more on how this happens.)

This reaction to Mueller in right-wing media was predictable enough. Similar things have happened so many times before, and been studied, analyzed, and documented. But to this day, no one knows how to stop or counter it. Mainstream institutions seem as unable as ever to resist its warping effects. It’s all playing out like some morbid script that we can only watch, stupefied.

Say he pardons everyone. People will argue on cable TV about whether he should have. One side will say up, the other will say down. Trump may have done this, but what about when Obama did that? What about Hillary’s emails? Whatabout this, whatabout that, whatabout whatabout whatabout?

There is no longer any settling such arguments. The only way to settle any argument is for both sides to be committed, at least to some degree, to shared standards of evidence and accuracy, and to place a measure of shared trust in institutions meant to vouchsafe evidence and accuracy. Without that basic agreement, without common arbiters, there can be no end to dispute.

If one side rejects the epistemic authority of society’s core institutions and practices, there’s just nothing left to be done. Truth cannot speak for itself, like the voice of God from above. It can only speak through human institutions and practices.

The subject of climate change offers a crystalline example here. If climate science does its thing, checks and rechecks its work, and then the Republican Party simply refuses to accept it ... what then?

That’s what US elites are truly afraid to confront: What if facts and persuasion just don’t matter anymore?

As long as conservatives can do something — steal an election, gerrymander crazy districts to maximize GOP advantage, use the filibuster as a routine tool of opposition, launch congressional investigations as political attacks, hold the debt ceiling hostage, repress voting among minorities, withhold a confirmation vote on a Supreme Court nominee, defend a known fraud and sexual predator who has likely colluded with a foreign government to gain the presidency — they will do it, knowing they’ll be backed by a relentlessly on-message media apparatus.

And if that’s true, if the very preconditions of science and journalism as commonly understood have been eroded, then all that’s left is a raw contest of power.