WATCH: CNN's Don Lemon calls BS on Trump advisor's conspiracy theory Obama was spying on Trump

In an epic back and forth, CNN host Don Lemon called out the absurdity of Stephen Moore's argument that the Trump campaign was infiltrated by a government spy somehow dispatched personally by former President Barack Obama.

Moore tried to claim that President Donald Trump isn't angry or lashing out at his Justice Department, rather he's "incensed" at Obama's Justice Department for allegedly investigating him. It's unclear if Trump or Moore knows that they're primarily the same department with the same civil service staff. It's only the political appointees that change with each president.

Moore demanded to know "doesn't it trouble you at all" to Lemon, to which Lemon flatly said no.

"Because there is no evidence that it happened," Lemon said of the claim that Obama was spying on Trump. "It is a complete red herring. All built on conspiracy theories and residents of Capitol Hill are going along with it. You guys did the same thing with the whole unmasking thing which turned out to be nothing, which turned out to be a conspiracy theory, and this is a conspiracy theory as well. So, we should investigate things on conspiracy theories? The entire [special counsel Robert] Mueller investigation, how many people have pleaded guilty in the Mueller investigation?"

Moore tried to say that as a former member of the Trump campaign if the Mueller team "came after me, it would cost me a quarter of a million dollars to defend myself. I would have been potentially charged with prison sentences."

Lemon explained that it wouldn't be the case so long as Moore didn't do anything illegal.

Former Republican and Russian-American author Max Booth noted that if Trump was innocent he wouldn't be so resistant to have an investigation. Instead he would welcome anything that would prove his innocence. Trump has opted for another approach, leading many to wonder if he is guilty after all.

When Trump first entered the presidency he accused former President Obama of wiretapping him in Trump Tower. That proved to be false also.

Watch the conversation below: