Donald Trump is living rent-free in President Barack Obama’s head.

In the past six months, Obama appears unable to resist condemning the presumptive Republican presidential nominee, criticizing his rhetoric on issues including terrorism, trade, illegal immigration, and the economy.

No matter where Obama goes or what he does, the people surrounding him repeatedly question him about the possibility that the controversial New Yorker could be his presidential successor.

“One of the grandest ironies of this political year is that a giant real estate developer in New York is currently living rent-free in President Obama’s head,” CNN’s Jake Tapper noted on Wednesday, after Obama delivered a six-minute lecture on whether Donald Trump was a populist.

Trump, Obama argues, is unfit for the serious job of the presidency. Obama has apologized for Trump’s controversial rhetoric when it has shaken political leaders around the world.

The president has accused Trump of being racist, sexist, xenophobic, Islamophobic, and a con-man, mocking him for being a reality television star selling a bunch of “okeydoke.”

Watch a highlight video of Obama responding to Trump below.

“I would’ve enjoyed campaigning against Trump,” Obama said in an interview with Bill Simmons last October. “That would’ve been fun.”

But the president doesn’t appear to be enjoying himself. Instead, he appears annoyed, angry, disjointed, and disturbed as he warns Americans and the media about the man campaigning to “Make America Great Again.”

“This is one of the prerogatives of when you’re at the end of your term,” Obama said in Canada during a press conference on Wednesday. “You go on these occasional rants.”