Congratulations, Elon Musk! Trump is your problem now.

Donald Trump's potential return to Twitter could bring a whole new minefield for Elon Musk to navigate.

Musk, who has struck a deal to buy Twitter for $44 billion, said this week that he will lift its permanent suspension of the former president — part of a pledge to restore “free speech” to the social media platform. But Musk also held out the possibility of temporarily suspending people who post content that’s illegal, directly incites violence or is otherwise “destructive to the world.”

Trump’s critics say his past tweets crossed that line repeatedly — and if Twitter lets him return, his flagrant disregard of the social network’s rules will become Musk’s headache.

“Musk is discovering all the questions that thousands of people at lots of different platforms have been wrestling with for decades,” said Joshua Tucker, a co-director of the NYU Center for Social Media and Politics. “You can already see Musk in his own statements waffling around. First — 'It's gonna be a free speech platform,' to 'Maybe tweets could be made invisible,' to 'Maybe they could be removed,' to 'Maybe people could be temporarily suspended.'”

For years, Trump used his favorite social media megaphone to insult his opponents, hurl racially or ethnically tinged rhetoric, spread misinformation about topics like elections and public health, and threaten violence against targets such as civil rights protesters and North Korea. That was long before Twitter booted him following his praise of the rioters who attacked the U.S. Capitol on Jan. 6, 2021.

People who have followed his long Twitter career don’t expect him to change if he returns to the site.

“I wish we saw a new Trump who actually learned from his actions. But I feel like these limitations that have happened have almost emboldened him to do more of the same,” said Laura Manley, the executive director of Harvard University’s Shorenstein Center on Media, Politics and Public Policy. “When he's coming on as a guest on talk shows, or anytime he has the microphone, he is still talking about how the election was rigged.”

Trump has said he doesn’t even want to rejoin Twitter, where he had nearly 89 million followers. (He has a reported 2.7 million followers on his newly created social network, Truth Social.) But he could easily change his mind.

So it’s a good occasion to revisit some of Trump’s most notorious, rule-breaking or controversial tweets — a possible taste of what could lie in the network’s future:

Pushing the envelope, with impunity

Some Trump critics were urging Twitter to kick him off even before he was sworn in, citing his use of the platform to denigrate people who opposed him and make baseless claims of fraud in the 2016 election.

Calls for the company to discipline Trump only increased once he became president — even as Twitter said his early posts didn’t violate its policies against harassment, racist or xenophobic rhetoric or threats of violence.

One early flashpoint: the executive order Trump issued a week into his presidency banning travelers and refugees from several Muslim-majority countries. He accompanied the action — and defended its sudden unveiling — with tweets that described Muslim immigrants “as a lot of bad ‘dudes’” and “bad people (with bad intentions)."

Trump’s tweets about North Korea’s nuclear program provoked even more alarm — including a September 2017 post, warning that leader Kim Jong-Un and his regime “won’t be around much longer,” that the country’s foreign minister labeled a “clear declaration of war.”

Twitter publicly declined to take down that tweet, citing the “newsworthiness” of Trump’s remarks. And the president kept at it, for instance with a jibe at Kim in January 2018 boasting that Trump’s “Nuclear Button” is “a much bigger & more powerful one than his, and my Button works!” Twitter also let that one remain up.

In another series of tweets from July 2019 aimed at four Democratic lawmakers who are women of color — Reps. Alexandria Ocasio-Cortez (N.Y.), Rashida Tlaib (Mich.), Ayanna Pressley (Mass.) and Ilhan Omar (Minn.). Trump called for them to “go back and help fix the totally broken and crime infested places from which they came.” All the lawmakers were born in the U.S. aside from Omar, who had been born in Somalia but emigrated to the U.S. in the 1990s.

Twitter didn’t take action on these tweets.

Twitter also didn't act on an August 2018 tweet in which Trump described former White House aide Omarosa Manigault Newman as “that dog,” provoking a new round of outrage at the insults he leveled at Black Americans who had criticized him.

Still, Twitter’s leaders warned that they could boot Trump if his tweets went too far over the line. The platform’s allowance for newsworthiness “is not a blanket exception for the president or anyone else,” the company’s legal and policy chief, Vijaya Gadde, told POLITICO in an interview in September 2018.

The following year, the company announced a policy change that would allow it to take punitive action against world leaders who violate its rules — a move that many at the time saw as a response to Trump’s incendiary posts. Twitter said it would continue to leave offending posts up in the name of newsworthiness, but in some cases would append warning labels or limit the tweet’s spread.

The George Floyd protests

Twitter’s crackdown began in the spring of 2020, as Trump lashed back at the racial-justice protests that sprang up following the killing of George Floyd by a Minneapolis police officer.

In a tweet on May 29, Trump called protesters in Minneapolis “THUGS” and appeared to threaten violence against the protesters, saying that “when the looting starts, the shooting starts.”

Twitter added a public interest notice to the tweet, saying it “violates our policies regarding the glorification of violence” and barred individuals from retweeting it — but only after it had been shared more than 23,000 times. The company said it allowed the tweet to stay up because of its “relevance to ongoing matters of public importance.”

Twitter took similar action on a tweet May 30 in which Trump threatened that protesters would be “greeted with the most vicious dogs, and most ominous weapons” if they breached the White House fence. Twitter also labeled that tweet as glorifying violence.

Covid-19 misinformation

Twitter flagged numerous Trump tweets for violating its policies by spreading false information about Covid-19. In one tweet on Oct. 11, 2020, after he recovered from Covid, Trump claimed he was now immune from the virus — a statement Twitter called misleading and potentially harmful, because even people who have been infected can still get the disease multiple times and still spread it.

The 2020 presidential election

Trump had spent years making false statements about the 2016 presidential election that put him in the White House — for example, tweeting that he had “won the popular vote if you deduct the millions of people who voted illegally.” (No evidence supports that claim.)

Twitter stepped in when Trump began warning that massive fraud would mar the 2020 presidential contest.

In May 2020, the company added fact-checking warnings to his tweets for the first time, flagging two posts in which he baselessly claimed that mail-in ballots were likely to be “substantially fraudulent.” Trump responded by issuing an executive order calling on federal regulators to roll back legal protections for social media platforms that restrict their users’ speech.

Twitter further expanded its election misinformation and civic integrity policies in September 2020, saying it would label or remove “false or misleading information that could undermine public confidence in an election or other civic process.”

Trump continued to be a repeat offender.

Twitter slapped fact-check labels on Trump tweets the day after the November 2020 election, saying he had violated its policies by falsely alleging that “surprise ballot dumps” had altered the results.

Twitter also labeled other tweets in which Trump alleged that Democrats were trying to “STEAL the Election.” But Trump continued claiming election fraud and calling for the results to be overturned during the next two months.

Violence on Jan. 6

The end came soon after Jan. 6, 2021, the day Congress was due to certify Joe Biden’s victory — even as Trump continued using Twitter to urge Vice President Mike Pence to intercede.

As a throng of Trump supporters began rampaging through the Capitol, battling police officers and calling to “hang Mike Pence” as a means to stop the election certification, the president put out a series of posts that Twitter flagged for violating its election and civic integrity policies. Those included one in which he said Pence “didn’t have the courage” to reject the election results — something multiple legal scholars, and Pence himself, say he didn’t have the power to do.

Twitter removed a later tweet in which Trump seemed to justify the deadly attack and told the rioters to “Go home with love & in peace. Remember this day forever!”

Two days later, Twitter said it had enough.

On Jan. 8, Trump posted a tweet saying that “American Patriots” who voted for him “will not be disrespected or treated unfairly in any way, shape or form!!!” And later in the day he tweeted: “To all of those who have asked, I will not be going to the Inauguration on January 20th.”

Twitter didn’t initially label or remove these two tweets. But later on Jan. 8, Twitter said they were the reasons that it ultimately booted Trump — permanently suspending his personal account, @RealDonaldTrump.

“These two Tweets must be read in the context of broader events in the country and the ways in which the President’s statements can be mobilized by different audiences, including to incite violence,” the company said in a blog post explaining its permanent suspension of Trump’s account. Twitter also permanently suspended the Trump campaign’s account, and removed offending tweets from the White House’s official @POTUS account, where Trump had vowed that “We will not be SILENCED!”

Days later, Facebook and Google-owned YouTube followed suit with similar bans — although theirs are not permanent.

Musk’s dilemma

Nearly a year and a half later, Twitter appears likely to be the first platform to roll out its welcome mat for Trump once again. Ousting Trump was “morally bad” and “foolish in the extreme,” Musk said this week.

Either way Musk decides on any posts by Trump, it's likely to draw scrutiny from Congress. A number of Democratic lawmakers are already calling for hearings to examine Musk’s plans for the company. And Republicans — who are cheering the Musk takeover — could just as easily become his new enemy if he lets Trump back on only to then curtail his posts.

“Anyone who tells you where this is going to land doesn't know the answer to that question,” said Tucker, of NYU. “We really don’t."