Hillary Clinton may spend her days hiking the woods of Westchester, but she has clearly set up camp in President Donald Trump’s head.

On Sunday morning, five months after his inauguration and 229 days since Election Day, Trump tweeted yet another broadside against his long vanquished campaign opponent, his 29th such tweet since winning the presidential election more than seven months ago.

“Hillary Clinton colluded with the Democratic Party in order to beat Crazy Bernie Sanders,” the president tweeted. “Is she allowed to so collude? Unfair to Bernie!”

“Collude” is a charged word in the Trump White House—the president is still dogged by investigations into whether he or members of his inner circle colluded with the Russian government to release damaging information about Clinton during the campaign—and the president has long relied on the I’m-rubber-you’re-glue strategy of deflecting accusations made against him back on his opponents.

But why does Trump still see Clinton as his opponent?

Why does Trump hand out maps of his Electoral College victory to Oval Office visitors as souvenirs? Why does he tell newspapers to run that same map on their front pages to commemorate his 100th day in office? Why do all roads lead back to Chappaqua?

Some close to the president see the fixation on the election as a counterpoint to what Trump views as unfair attacks on his legitimacy.

“In my view, this is all about the president’s view of the media coverage,” Chris Ruddy, CEO of Newsmax Media and longtime Trump confidant, told The Daily Beast. “He is essentially saying to the press, ‘Hey, you are making a big issue of my campaign’s ‘collusion’ with Russians when there is no evidence of it, but when you do have evidence that Hillary colluded with the DNC against Sanders, it’s basically a non-story.’”

Those insecurities are compounded by the ever-circling special counsel investigations into his campaign’s potential Russia connections, and now the investigation into whether Trump attempted to obstruct justice.

Others see in Trump’s continued insistence on holding campaign-style rallies—including one in Iowa on Wednesday, in which the president repeatedly lashed out at Clinton, to chants of “lock her up!”—a preference for attention over administration.

“Trump clearly prefers campaigning to governing,” Brian Fallon, Clinton’s former campaign press secretary, told Politico. “He is desperately in search of an enemy to be a political foil and help take the media focus off his own scandals.”

Clinton, for her part, has clearly taken a Pete Souza-style joy in subtle (and not-so-subtle) jabs at the president from outside the bars of his cage. Most presidential hopefuls retreat from the public eye after the humiliation of a failed bid for the White House—Al Gore disappeared for nearly a year, returning with a spare tire and a Failure Beard. But Clinton, operating under the fair assumption that Trump’s itchy Twitter fingers will make her relevant again with the slightest provocation, has pulled out all the stops in inciting the president’s mockery, from cringeworthy lampoons of his Twitter typos to implicitly comparing him to President Richard “Dick” Nixon.

“We were furious about the past presidential election of a man whose presidency would eventually end in disgrace with his impeachment for obstruction of justice,” Clinton said in May while delivering the commencement address at her alma mater, Wellesley College, “after firing the person running the investigation into him at the Department of Justice.”

The president’s rearview-mirror focus, in this case, even managed to spread to the rest of the Republican party. After the speech, Ronna McDaniel, the chair of the Republican National Committee, launched an attack on the candidate who had lost seven months before, calling the address “a stark reminder of why Hillary Clinton lost in 2016.”

Even Trump’s detractors see the perpetual Clinton bashing as hampering his ability to implement his administration’s agenda. Jim Messina, a former deputy chief-of-staff during the Obama administration and co-chair of pro-Clinton SuperPAC Priorities USA Action, told The Daily Beast that even the president’s fans are “getting exhausted” by his metronomic revisiting of the 2016 campaign.

“A key factor for successful presidential campaign and popular presidencies is a focus on the future. Americans quite simply just want to hear is how that person is going to make their lives better,” Messina said. “Even Trump's core supporters will be getting exhausted hearing about the 2016 election but its not clear that this Trump is capable of focusing on anything other than past grievances. My strong feeling is voters will begin to understand none of this drama is about how their lives are actually getting better.”

But with Trump’s health care plan facing a Himalayan climb in the U.S. Senate, a much-lauded tax code overhaul currently in the doodling-on-bar-napkins stage, and the aforementioned obstruction of justice investigation, those close to the president told The Daily Beast that they wish he would keep his mind on absolutely anything other than Clinton.

“He should avoid looking back, ignore most of the media attacks, and focus on the positive things that will create prosperity,” Ruddy told The Daily Beast. “The real Donald Trump is a man who can bring people together and get things done!”