Sunday on CBS’s “Face the Nation,” RNC chairman and incoming White House chief of staff Reince Priebus backed President-elect Donald Trump’s tweet claiming millions voted illegally.

In addition to winning the Electoral College in a landslide, I won the popular vote if you deduct the millions of people who voted illegally

Partial transcript as follows:

DICKERSON: Let me ask you, as the incoming chief of staff, what do you do when he says something like millions of voters voted illegally in California when you know that’s not true?

PRIEBUS: Well, I don’t know if that’s in the true, john. i saw there was an article in the “Wall Street Journal” the other day, and it had a certain percentage of people that are voting that shouldn’t be voting. There are estimates all over the map on that. Here’s the problem, no one really knows.

DICKERSON: But you think millions of people voted illegally?

PRIEBUS: It’s possible.

DICKERSON: There is no evidence that it happened in millions of votes in California. I guess is question is: when you’re president, can you just offer a theory that has no evidence behind it, or does he have to tighten up his standard of proof?

PRIEBUS: I think he’s done a great job. I think the president-elect is someone who has pushed the envelope and caused people to think in this country. He’s not taking conventional thought on every single issue. It’s caused people to look at things that maybe they’ve taken for granted. Look at the flag-burning issue last week. This is an 80% issue. you watch the news media and they say it’s Constitutional. Well, right, it is Constitutional, but it doesn’t mean it’s in the a subject for debate and discussion for the Supreme Court to revisit down the road. So I think he… I think that unconventional thought is something that has caused a revolution in this country, which is why I think President Trump will go down in history as a really great president.