Charles Krauthammer told viewers Tuesday on "Special Report with Bret Baier" that the historical factor regarding Hillary Clinton clinching the Democratic presidential nomination will be “very much minimized and muted."

Clinton is the first woman to clinch a major party's presidential nomination.

“It will probably last for an hour or two tonight, but after all she’s essentially been running for 16 years. She was expected to be the nominee in 2008,” Krauthammer, a syndicated columnist and Fox News contributor, said.

"She was going to be coronated this time around so there was a delayed feeling," Krauthammer said, adding, "We had the first African-American, which I think was a far more improbable proposition, 8 years ago."

“This is less of a reverberating event,” Krauthammer said. “The fact is… Democrats are worried, and should be worried, simply because you can’t use the usual playbook against Donald Trump.”

Krauthammer argued the Clinton campaign is nervous about running against Trump because “Democrats know how to run against conservatives. They don’t know how to run against a populist who was unexpected, unpredictable and can do anything.”