Jimmy Fallon has come under fire after interviewing Donald Trump on Thursday by critics who say he wasn't aggressive enough with the presidential candidate.

Fallon's playful, softball interview, which ended with his toughest question — whether Trump would let him mess up the candidate's hair — has inspired a lot of heated criticism among viewers and members of the media.

Huffington Post writer Maxwell Strachan called the interview "an extended on-air puff piece" and dinged Fallon for playing nice with a controversial figure running for the highest job in the nation. Strachan compared Fallon's Trump interview with one done by David Letterman, who retired from late night last year.

"At their best, late-night hosts have been able to toe a difficult line between comedy and responsibility. No one did this better than David Letterman, who repeatedly exposed truth while still on the air," Strachan wrote.

He continued: "Fallon is not Letterman, and he never will be, nor does he seem to want to be. But that doesn't mean he be let off the hook for humanizing a well-documented xenophobic, racist, and misogynistic serial liar, which is exactly what he did on Thursday."

A chorus of viewers expressed their anger with Fallon on social media:

—Matt Zoller Seitz (@mattzollerseitz) September 16, 2016

A "Tonight Show" representative didn't immediately respond to Business Insider's request for comment.

Watch a clip from Fallon's Trump interview: