Reince Priebus shakes hands with President-elect Donald Trump on election night. (Jim Watson/Agence France-Presse via Getty Images)

One would think that Reince Priebus, the guy in charge of the Republican Party's 2016 electoral efforts, would be unwilling to entertain the nonsensical idea that millions of people who participated in it voted illegally. After all, the Republicans did very well in 2016 — holding the Senate, holding the House and retaking the White House. And, after all, it would largely be up to Priebus as head of one of the two major political parties to maintain the integrity of the election — and up to the Republican attorneys general in the majority of the states to police things.

That policing happens, of course. Any number of safeguards and protections are in place to ensure the integrity of the vote. Over the course of the election, we found a grand total of four proven instances in which someone was caught trying to vote more than once in person or by absentee ballot. The system works, and Priebus should both know and reiterate that point.

Confronted by CBS's John Dickerson on Sunday morning, though, he didn't.

Priebus, Trump's incoming chief of staff, points to this Wall Street Journal article as evidence for claims of illegal voting. He hops, skips and jumps from it to his broad assertion that “it's possible” millions of people cast illegal ballots.

First, to that article. It's an opinion piece, offered by two longtime advocates for increased election security. The assertion they make is that “there is a real chance that significant numbers of noncitizens and others are indeed voting illegally, perhaps enough to make up the margin in some elections.” The key words there are “significant,” “and others” and “some” — close contests decided by a handful of votes could indeed be swayed by a handful of people who broke the law. But the article very clearly doesn't argue that in this election millions of people voted illegally — much less that any significant number of noncitizens did so.

We will also note that it almost certainly isn't possible that millions of people voted illegally. Statistical analysis of the 2016 results shows no pattern that would suggest any significant number of votes from noncitizens, which is the sort of analysis that you can't fake. As we and The Washington Post's fact-checkers noted last week, the idea that millions of voters cast illegal ballots stems mostly from a tweet from one guy, for which no evidence was offered and which was picked up by the conspiracy-hawking site InfoWars.

Well, to be more specific, the claim to which Priebus was responding came from a tweet from his new boss, President-elect Donald Trump. This tweet:

That's not true.

On ABC's “This Week,” Vice President-elect Mike Pence also tried to defend Trump's words.

“I think that four years ago, Pew Research Center found that there were millions of inaccurate voter registrations,” Pence said. That's true — but it bears no relationship to what Trump alleged this year. Ever moved without canceling your voter registration at your old residence? Pence implies that this means you voted twice.

“I don't know that that is a false statement, George,” Pence told host George Stephanopoulos, “and neither do you.” Stephanopoulos may, actually, assuming that he has reviewed the evidence at hand. And, for the 100th time, the way making broad claims works is not that anyone can say anything and others have to prove them wrong. If I say that 90 percent of Americans read every article I write, we don't assume that's true until you somehow disprove it. (It is true, though.)

What's remarkable about this particular issue is that it's fairly easy to answer without reinforcing Trump's falsehood: “The president-elect is concerned about Americans having confidence in our elections, John/George, and we will work to bolster that confidence.” Something like that. You can talk about what Trump said and what his concerns are without defending false nonsense.

Or, you could point out that this particular opinion isn't true. That's a bit tricky; Priebus works for the guy. But the unavoidable question here is the boundary of where Priebus and Pence will stop defending things Trump makes up. Trump makes up a lot of things, all the time. Some are fairly innocuous. Some, like this, are potentially more harmful. Some, like when he lied about having seen Muslims celebrating in New Jersey on 9/11, might be tremendously harmful in their implications.

If Trump asserts without evidence that some violent incident is the work of Muslim terrorists — as he has in the past — what will the response be from Priebus, Pence and other Trump defenders? What if he continues to insist something that's false is true on a subject that is potentially more damaging to the American public? When and where will people push back? It's fair, too, to wonder about the extent to which they can or do push back in private. Whether Trump actually believes what he's saying is one thing; it's very fair to assume that his tweet above was simply meant to save face in light of Hillary Clinton having soundly beaten him in the popular-vote margin. If he brings such a falsehood into a private conversation with his top advisers, though, will they at least push back on his claims there?

Pence, in his trademark amused-slash-dismissive way, explained Trump's behavior to Stephanopoulos like so:

“I think he's expressed his opinion on that,” Pence said. “And he's entitled to express his opinion on that. I think the American people find it very refreshing that they have a president who will tell them what's on his mind . . . He's going to say what he believes to be true, and I know that he's always going to speak in that way as president.”

Trump saying what he believes to be true vs. what is true is fine with Pence and, as he implies, fine with Trump's supporters. There are two spheres involved here: the sphere of falsehood with Trump at the center and the sphere of accuracy, where the center is held mostly by members of the media. That's why Trump consistently positions the media as dishonest, as he did at his victory/campaign rally on Thursday: His position is strengthened when ours is weakened.

The stakes in this voter-fraud thing are fairly low but not insignificant — and Priebus and Pence don't blink in having Trump's back.

If the stakes are raised, though?

What then?