Late-night comedians Stephen Colbert and Jimmy Fallon targeted President Trump in 97% of their jokes about presidential candidates during September, according to a study by the Center for Media and Public Affairs at George Mason University.  

“When Trump’s onstage, everyone else is blacked out,” George Mason communication professor Robert Lichter told the Associated Press when speaking about the study.  

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The study indicated that Colbert and Fallon told 455 jokes about Trump and only 14 against Democratic nominee Joe Biden. The comedians made an additional 64 jokes about Trump’s family and administration.  

Jimmy Fallon plays with then-Republican presidential candidate Donald Trump's hair on a Sept. 15, 2016 episode of 'The Tonight Show'

Jimmy Fallon plays with then-Republican presidential candidate Donald Trump's hair on a Sept. 15, 2016 episode of 'The Tonight Show' (YouTube)

Lichter told the AP that he’s been studying late-night humor and politics since 1992 and that Republicans are usually lampooned more than Democrats -- but he said the difference is drastic this year.  

Back in 2016, Trump was the punchline for 78% of jokes compared to 22% for Hillary Clinton. Lichter said he believes comedians will continue to mock Trump regardless of the outcome of Election Day.  

“I think they will find a way to keep making jokes about Trump, even after he leaves office,” Lichter said. 

Colbert, who is typically more political than Fallon, is an outspoken critic of Trump but recently expressed support for the president when he was transported to Walter Reed National Military Medical Center after testing positive for coronavirus.  

Colbert pointed out the seriousness of the president's diagnosis as the presidential election is on the horizon. 

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"Now, say what you will about the president, and I do," Colbert said. "This is a serious moment for our nation and we all wish the president and the first lady of the United States a speedy and a full recovery." 

“I really think it's important for all of us to separate the man from the office – and I hope on Nov. 3 we literally do. But for now, I find it troubling, moving even, to see the president of the United States be taken to the hospital and to imagine the responsibility those service members flying that helicopter must feel," Colbert added. 

Fox News’ Melissa Roberto contributed to this report.