Democratic Pennsylvania gubernatorial candidate Josh Shapiro’s campaign dredged up a past thesis written by GOP candidate Doug Mastriano in a new ad on Thursday, marking the campaign’s latest effort to paint the Republican as an extremist. 

The 30-second ad, titled “Strange Ideas,” cites a 2001 thesis written by Mastriano in which he warned that a left-wing “Hitlerian putsch” against the U.S. military would destabilize the country.

The Hill was the first outlet to view the ad, which will air across Pennsylvania. 

“When he was 37, he wrote a bizarre manifesto, predicting someday someone like himself would have to hide out in a cave because he feared a politically correct leader driven by deviant sexual behavior would take over America and kill millions,” the ad’s narrator says. “Mastriano warned that only a macho warrior spirit could save us. And now he wants to be our governor?”

The thesis, which was reported by The Washington Post in May, is titled “The Civilian Putsch of 2018: Debunking the Myth of a Civil-Military Leadership Rift.” Mastriano was a U.S. Army major at the Air Command and Staff College at the time.

It’s written from the perspective of a military colonel hiding in a forest after a dictator has gotten rid of the Constitution and declared martial law in the U.S., and millions have perished in a purge.

The Hill has reached out to the Mastriano campaign for comment. 

The attack comes as other Democrats increasingly go on the offense against their GOP opponents, painting them as extremists. The strategy can be traced all the way to the top of the party, with President Biden directly targeting former President Trump. 

Earlier this month at Independence Hall in Philadelphia, Biden warned that Trump and “MAGA Republicans” who back his views pose a grave threat to the country’s democratic values. 

“As I stand here tonight, equality and democracy are under assault,” Biden said. “Too much of what’s happening in our country today is not normal. Donald Trump and the MAGA Republicans represent an extremism that threatens the very foundations of our republic.”

Polls show Shapiro leading Mastriano in the closely watched gubernatorial contest. A CBS-YouGov poll released on Wednesday had Shapiro leading Mastriano 55 percent to 44 percent.