Sen. Ted Cruz (R-Tex.), right, gestures at rival GOP presidential candidate Donald Trump at the Republican primary debate in Detroit on March 3. (Jim Young/Reuters)

Plenty of Republicans have announced their support for Donald Trump after saying nasty things about him. Marco Rubio called Trump a "con man." Chris Christie dismissed him as the "entertainer in chief." Both are now on board.

But nobody's support for Trump seemed as unlikely as Ted Cruz's. Cruz even clashed with Trump during the Republican National Convention two months ago, causing a scene that many thought presaged a potential Cruz 2020 presidential bid — even against an incumbent President Trump.

For whatever reason, Cruz has now decided he will support Trump. But it's worth recapping how unlikely that sentence I just wrote once seemed.

Behold: Nine truly awful things Ted Cruz and Donald Trump have done to or said about one another:

1. Trump retweeted an unflattering photo of Cruz's wife, Heidi, juxtaposed with his wife, Melania.

This tweet still hasn't been deleted.

2. Trump threatened to "spill the beans" on Heidi Cruz.

We're not entirely sure what this meant. But it was certainly a threat.

3. Trump suggested that Cruz's father may have been involved in the Kennedy assassination.

Among the bizarre events in this campaign, this surely ranked toward the top:

"His father was with Lee Harvey Oswald prior to Oswald being, you know, shot," Trump said during a telephone interview. "I mean the whole thing is ridiculous. What is this? Right? Prior to his being shot. And nobody even brings it up. I mean, they don't even talk about that — that was reported. And nobody talks about it."

Trump seemed to be talking about a photo published last month by the National Enquirer that shows Oswald and another man distributing pro-Castro leaflets in New Orleans in 1963. The tabloid claims that the second man is Rafael Cruz, the Republican presidential candidate's Cuban-born father, an explosive accusation that has not been corroborated, according to the Miami Herald. At the time, the Cruz campaign told the Miami Herald: “The story is false; that is not Rafael in the picture.”

Trump's timeline of this explosive accusation was rather unclear; he seemed to refer to an alleged meeting that happened before Kennedy's assassination on Nov. 22, 1963, and Oswald's death two days later. Trump later added: "I mean, what was he doing with Lee Harvey Oswald shortly before the death, before the shooting? It's horrible."

The day after the Republican National Convention ended, Trump brought it up again.

4. Cruz said Trump "slandered" his wife. And that he's not a "servile puppy dog."

Sen. Ted Cruz (R-Tex.) explained why he did not endorse Republican presidential candidate Donald Trump for president, saying "I am not in the habit of supporting people who attack my wife and attack my father." (Reuters)

Part of the reason Trump revived the Rafael Cruz-Kennedy-assassination conspiracy theory after the convention is that Cruz had just snubbed him in a big way.

After delivering a speech to the Republican National Convention in which he conspicuously didn't urge people to vote for Trump — and was booed for it — Cruz doubled down the next morning.

"I am not in the habit of supporting people who attack my wife and attack my father," Cruz said. "That pledge was not a blanket commitment that if you go and slander my wife that I am going to come like a servile puppy dog for maligning my wife and maligning my father."

5. Cruz called Trump a "sniveling coward."

After the "spill the beans" attack, Cruz had this rejoinder:

“It’s not easy to tick me off,” Cruz said. “I don’t get angry often. But you mess with my wife, you mess with my kids, that’ll do it every time. Donald, you’re a sniveling coward. Leave Heidi the hell alone.”

6. Cruz said Trump is a "pathological liar," "utterly amoral" and a "serial philanderer."

Republican presidential candidate Ted Cruz attacked rival Donald Trump in Indiana, calling him a "bully," "pathological liar" and a "serial philanderer" after Trump made comments associating Cruz's father with JFK's assassin. (The Washington Post)

In a news conference after the initial Rafael Cruz allegation was made and as Cruz was about to absorb a damaging loss in the Indiana primary, Cruz unloaded on Trump for really the first time, calling him "a narcissist at a level I don't think this country's ever seen."

"He is proud of being a serial philanderer," Cruz said.

"This man is a pathological liar. He doesn't know the difference between truth and lies," Cruz added. "In a pattern that is straight out of a psychology text book, he accuses everyone of lying."

And: "Whatever lie he's telling, at that minute he believes it."

And: "The man is utterly amoral."

And: "Donald is a bully. Bullies don't come from strength; they come from weakness."

7. Trump breathed life into the Cruz "birther" conspiracy.

Trump suggested strongly early in the primary season that Cruz might not be eligible to serve as president, given his birth in Canada to an American citizen.

“Republicans are going to have to ask themselves the question: ‘Do we want a candidate who could be tied up in court for two years?’ That’d be a big problem,” Trump said. “It’d be a very precarious one for Republicans because he’d be running and the courts may take a long time to make a decision. You don’t want to be running and have that kind of thing over your head.”

For more on the Cruz-birther thing, see here.

8. Trump said he wouldn't even accept Cruz's endorsement.

"If he gives it, I will not accept it," Trump said after the GOP convention.

"I don't want his endorsement," he added. "Just, Ted, stay home, relax, enjoy yourself."

9. Trump attacked Cruz's faith.

More than once.

"To the best of my knowledge, not too many evangelicals come out of Cuba, okay?" Trump added in December while appealing to heavily evangelical Iowa. "Just remember that, okay? Just remember."