Donald Trump
U.S. President Donald Trump arrives aboard Air Force One at Orlando International Airport in Florida, March 3, 2017. Reuters

Last week, President Donald Trump tweeted — without evidence — a bombastic claim: that former President Barack Obama had wiretapped him during last year’s presidential election.

When reporters pressed him for evidence of the claim at the White House Friday, he ignored the questions and shuffled them out of the room.

FBI Director James Comey reportedly said the claims were false, and he pushed the Justice Department to refute the allegations. Armed with the knowledge that Trump hadn’t received the information from U.S. intelligence, reporters started digging. And they found that Trump probably obtained his information from a sketchy report from the right-leaning website Heat Street.

Read: What Is Libel vs. Slander? Trump Tweets About Obama Wiretapping Could Be Defamatory

The Obama wiretapping claim seems outrageous, but it’s actually the latest incident in a pattern of Trump making accusations with little — if any — root in reality. After all, Trump was one of the loudest proponents of the birther movement, a conspiracy theory that doubted the legitimacy of Obama’s citizenship.

"He doesn't have a birth certificate, or if he does, there's something on that certificate that is very bad for him,” Trump said in 2011. “Now, somebody told me — and I have no idea if this is bad for him or not, but perhaps it would be — that where it says 'religion,' it might have 'Muslim.' And if you're a Muslim, you don't change your religion, by the way."

In reality, Obama was born in Hawaii, has produced his birth certificate and identifies as a Protestant Christian. Here’s a list of five other conspiracy theories that Trump publicly embraced:

1. Massive voter fraud exists.

This is one of Trump’s favorite claim, and he made it repeatedly before — and after he won — the election.

“Let me just tell you — when you see illegals, people that are not citizens and they are on registration rolls,” Trump said in an interview with Bill O’Reilly last month. “Look, Bill, we can be babies, but you take a look at the registration, you have illegals, you have dead people, you have this, it's really a bad situation. It's really bad.”

In January, he threatened to launch an investigation into voter fraud although that has yet to come to fruition. However, as experts have said repeatedly, there has been absolutely no evidence of voter fraud or rigged elections.

Read: FBI Director James Comey Slams President's Alleged Wiretapping Claims

2. Muslims cheered as the World Trade Center crumbled.

This claim has a particularly nasty edge for American Muslims in 2017, especially after Trump introduced a revised executive order temporarily banning travelers from six Muslim-majority countries earlier this week.

"I watched when the World Trade Center came tumbling down," Trump said in November 2015. "And I watched in Jersey City, N.J., where thousands and thousands of people were cheering as that building was coming down. Thousands of people were cheering."

Again, there was no evidence to back that claim — even Trump had previously said he was in Manhattan during the terrorist attacks — and PolitiFact rated the statement Pants on Fire.

3. Ted Cruz’s father was involved in the assassination of John F. Kennedy.

"[Cruz’s] father was with Lee Harvey Oswald prior to Oswald being, you know, shot. I mean the whole thing is ridiculous. What is this, right, prior to his being shot? And nobody even brings it up," Trump said on Fox and Friends last May.

That claim received another Pants on Fire rating from PolitiFact. It’s likely Trump based this allegation on dubious photo evidence from the National Enquirer, a tabloid that doesn’t have the best reputation for accuracy.

4. Supreme Court Justice Antonin Scalia was murdered.

“[T]hey say they found a pillow on [Scalia’s] face, which is a pretty unusual place to find a pillow,” Trump said last February after Scalia died. “I can’t tell you what — I can’t give you an answer.”

Again, there is no evidence to support this statement — only conspiracy theories.

5. Climate change is a hoax invented by the Chinese.

In fact, scientists have come to the exactly opposite consensus: Climate change is very real, they say with evidence, and humans have played a major role in it.