President Donald Trump has spread conspiracy theories about his predecessor, President Barack Obama, for over a decade.

He most famously fueled a conspiracy theory that the President wasn't born in the United States and that his birth certificate was fraudulent. The false claim sparked racist fury against President Obama for the duration of his presidency.

And when he's not spreading conspiracy theories about him, Trump blames Obama for his own failures.

A recent retweet from Trump managed to do both of those things simultaneously.

Trump echoed claims from far-Right commentator David J. Harris that Obama was secretly running the investigation into Russian election interference in an effort to hurt Donald Trump.

This latest conspiracy theory didn't sit well with CNN's Don Lemon, who called out Trump's petty obsession with Obama during a primetime segment.

Watch below.

Lemon said:

"What is it about President Obama that really gets under your skin? Is it because he's smarter than you? Better educated? Made it on his own—didn't need Daddy's help? Wife is more accomplished? Better looking? I don't know, what is it, what is it about him? That he's a black man that's accomplished being president? That he punked you on the whole birth certificate thing? What is it about him? Just wondering."

In case you forgot, the President is by no means a fan of Don Lemon, frequently referring to him as "the dumbest man on television."

The President has yet to respond to Lemon's latest segment, but it's easy to imagine what he'd say.

Others are praising the host for his frankness.

The segment is likely to get under Trump's skin because nothing Lemon said was false.

For a deeper look into Trump's ineptitude, check out A Very Stable Genius, available here.