Former White House press secretary Sarah Sanders warned supporters of President Trump on Saturday night not to underestimate Sen. Bernie Sanders following his projected victory in the Nevada Democratic caucuses.

"I think [Bernie Sanders] is looking like the presumptive Democrat nominee at this point. He's certainly moving in that direction," Sanders said on "Justice with Judge Jeanine." "And I think Republicans have to be extremely careful. We can take nothing for granted at this point. The stakes have literally never been higher."

"We can take nothing for granted at this point. The stakes have literally never been higher."

— Sarah Sanders

BIDEN VOWS RESURGENCE AFTER SANDERS' WIN IN NEVADA: 'I'M GOING TO TAKE THIS BACK'

Bernie Sanders, who is no relation to Sarah Sanders, will win the Nevada caucuses, Fox News projected Saturday, furthering the democratic socialist's lead over his Democratic rivals and raising the question of whether he can be stopped on his path to the Democratic nomination.

Sarah Sanders noted the importance of Republicans voting in November to combat Bernie Sanders.

"If crazy socialist Bernie Sanders is the Democrat nominee, as he is well on track to be, literally the way of life and our very freedom is at stake at the election in November and Republicans have to come out in full force and make sure that they get Donald Trump reelected," Sanders said. 

"If crazy socialist Bernie Sanders is the Democrat nominee ... our very freedom is at stake ... Republicans have to ... make sure ... they get Donald Trump reelected."

— Sarah Sanders

Sarah Sanders highlighted the negatives of a Bernie Sanders coalition and listed Trump's strengths. 

"Bernie has a small kind of coalition that I think has a low ceiling. I think it's going to be hard for him to overcome that in a general election whereas the president has expanded very far beyond his 2016 base, in large part because of the success of his," Sanders said. "Say the economy is booming. Every demographic is doing better under this president and you're going to see that change the makeup of the voters that come out and support him in November."

Fox News' Paul Steinhauser and Adam Shaw contributed to this report.