Fox News' Greg Gutfeld said he is nervous for former Vice President Joe Biden's mental health and competence after the 2020 hopeful stumbled on the campaign trail when recalling the year that Sen. Robert Kennedy and Dr. Martin Luther King, Jr. were assassinated.

"Just like in my generation when I got out of school...when Bobby Kennedy and Dr. King had been assassinated in the '70s and they'd said well I got engaged you know up to that time remember that," Biden said at a campaign rally in Iowa Tuesday.

Biden's recollection was inaccurate, however, because King and Kennedy were murdered in 1968, about two months apart.

"It's sad," Gutfeld said on "The Five" Wednesday. "That actually makes me a little nervous. And the media has screwed it up for Biden because now you can openly question his mental acuity. You can discuss age-related mental decline, feebleness, even dementia because they labeled out that stuff, that narrative regarding Trump, for three years, so it's no longer unseemly. In fact, you could talk about this out of concern and I do think people on the Dems must be a little bit worried. I would be. I feel bad. I don't think it's that funny either."

IN LATEST GAFE, BIDEN PLACES KING, KENNEDY ASSASSINATIONS IN 'THE LATE '70S'

Fox News' Juan Williams countered Gutfeld, saying he's not worried "in the least" because Trump has had similar gaffes while in office that have flown under the radar.

"I remember Trump, just the other day, was talking about the Continental army was taking over airports," Williams said. "And then he said that a shooting that took place in Dayton took place in Toldeo."

"I think Republicans want to focus on the idea that Biden's old, or Biden's fading," Williams continued. "This is nothing new with Biden... his folks see charm."

Biden's poll numbers have remained strong despite a series of gaffes at campaign stops across the country, with him 11 points ahead of Sanders and his other contenders, according to a Fox News poll.

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Charm aside, Fox News' Katie Pavlich said Biden's blunders could potentially hurt him in the long run.

"He's running as the guy who's experienced, who's been in D.C., who is supposed to know what he's doing, and yet all of these things piling up show he doesn't necessarily know what he's doing and that his experience isn't helping him when it comes to these major events," Pavlich said. "If he's going to make that argument that he's more experienced and competent than President Trump, he's going to have to get his facts straight on basic things that he says he 'remembers.'"