Sean Spicer should have listened to Ari Fleischer.

After Spicer's flagrant misstatement of Inauguration Day crowd figures over the weekend, Fleischer — a former White House press secretary trying to help the current one — offered some free advice Monday on Fox News.

“As soon as a press secretary gets into statistics and facts, the press is going to fact-check the press secretary,” Fleischer said. “So don't use a fact, don't use a stat, unless you're 100 percent certain you've got it nailed down.”

Simple, right? Don't make trouble for yourself and your president by saying provably false stuff to reporters.

And yet! Spicer stood before reporters on Tuesday and delivered this whopper, in defense of President Trump's bogus claim that massive voter fraud cost him the popular vote in November: “I think there's been studies. There was one that came out of Pew [in] 2008 that showed 14 percent of people who have voted were not citizens.”

It is hard to overstate what a brazen lie this was. I say “lie” — a loaded word that suggests Spicer knew he was telling a falsehood — because it is inconceivable that he believed it to be true. Trump has mischaracterized Pew's research on more than one occasion, and fact-checkers have crushed him for it. There is no way that Spicer, whose job requires him to obsess over media coverage, did not know that this absurd claim has been debunked.

And just think about how ridiculously large that number, 14 percent, really is. Did Spicer really expect anyone — even people who believe, despite a lack of evidence, that voter fraud is a big problem — to buy the idea that 1 in 7 voters is not a U.S. citizen? And that a respectable outfit like the Pew Research Center would have published that kind of garbage?

For the record, Spicer appears to have conflated two different studies, neither of which showed what he said. In one, researchers at Old Dominion University surveyed noncitizens in 2008 and 2010 and asked whether they are registered to vote; 14 percent said yes.

There are reasons to be skeptical of that figure (explained in detail here), but let's go with it for a minute. A conclusion that 14 percent of noncitizens are registered to vote is very different from a conclusion that 14 percent of all voters are noncitizens. Noncitizens represent just 7 percent of the U.S. population. If 14 percent of them are registered to vote, we are talking about 1 percent of voters.

The second study, published by Pew in 2012, concluded that “approximately 24 million registration records, or nearly 13 percent of the national total, are estimated to be inaccurate or no longer valid.” Again, there is a big difference between inaccurate voter rolls and fraudulent ballots.

Voter registration records can be inaccurate for all kinds of reasons. After Spicer's news conference on Tuesday, I decided to check my registration status in Massachusetts, where I lived before moving to Virginia in the fall of 2015. Guess what? The Massachusetts secretary of state's office still says I'm active in the Bay State. I guess Bill Galvin doesn't know that I moved, which is kind of hurtful; I assumed that he missed seeing my byline in the Boston Globe.

Anyway, like 2.8 million people in the Pew study, I am apparently registered in more than one state. But that doesn't mean I actually vote in more than one state, and there is no evidence that tons of other people do, either.

Spicer knows this stuff. It's his job to know this stuff. Yet, with his credibility already damaged, he told the White House press corps another fat one on Tuesday.

With phony figures, Spicer is killing his standing among journalists — and it's only the first week of the Trump era.