This might be why Trump claimed his was the 'biggest' Electoral College win since Reagan

President Donald Trump erroneously claimed during a White House news conference Thursday that his Electoral College victory over Democratic nominee Hillary was "the biggest Electoral College win since Ronald Reagan" — but one sentence on the White House website could possibly help explain the error.

Responding to a question about whether his supporters might have bolstered anti-Semitic voices throughout the presidential campaign, Trump said he's the "least anti-semitic person you've ever met." The president continued by boasting about his Nov. 8 victory.

"I wasn’t supposed to get 222 [Electoral College votes]. They said there’s no way to get 222, 230’s impossible — 270, which you need, that was laughable. We got 306 because people came out and voted like they’ve never seen before, so that’s the way it goes," Trump said.

"I guess it was the biggest Electoral College win since Ronald Reagan," the president then added.

But later during the same news conference, NBC News reporter Peter Alexander fact-checked Trump on his claim.

"You said today that you had the biggest electoral margin with 304 or 306 electoral votes," Alexander said. "In fact, President Obama got 365."

Trump interjected by saying Obama was "not a Republican," as if to make the point that earlier he was only claiming he had the biggest Electoral College victory since Reagan — but only among Republican presidents. But as Alexander then pointed out, even that claim didn't hold water.

"George H.W. Bush [got] 426 when he won as president," Alexander said. "So why should Americans trust—"

But before Alexander could ask his question, Trump again interjected: "Well, no I was told — I was given that information."

Alexander continued with the rest of his question.

"Why should Americans trust you when you have accused the information they receive of being fake when you're providing information that's untrue?" the reporter asked.

Trump didn't provide a direct answer to the question but again noted that he was "given that information."

"Actually, I've seen that information around. But it was a very substantial victory. Do you agree with that?" Trump asked the reporter.

"You're the president," Alexander responded.

.@PeterAlexander fact checks Donald Trump on Electoral College results from previous elections. pic.twitter.com/LrlfCoocYU

— CSPAN (@cspan) February 16, 2017

Trump won the presidency not with 306 electoral votes, as he claimed Thursday, but with 304 electoral votes, compared with Democratic nominee's Hillary Clinton's 227 electoral votes, according to the National Archives and Records Administration.

Former President Barack Obama received 365 electoral votes in 2008 against Republican nominee Arizona Sen. John McCain. And in 2012, Obama won re-election with 332 electoral votes against former Massachusetts Gov. Mitt Romney.

It's possible Trump was referring to his own biography on the White House's official website, which correctly states that Trump "won the election on November 8 of 2016 in the largest electoral college landslide for a Republican in 28 years." That is, in fact, entirely true since former President George W. Bush barely defeated former Democratic Vice President Al Gore 271-266.

George W. Bush won his re-election against then-Sen. John Kerry (D-Mass.) with 286 electoral votes.