Fox News contributor Karl Rove said on Monday that there's still “a long way to go” before declaring Sen. Bernie Sanders, I-Vt., to be the clear frontrunner for the Democrat presidential nomination.

“Let’s be careful,” Rove told “America’s Newsroom,” explaining that commentators are moving too quickly when it comes to Sanders' lead.

Rove said that 3,979 delegates will vote at the Democratic National Convention, with the nominee needing to secure 1,991 to put them over the top.

“They have elected in the three contests thus far a grand total of 101 delegates to the Democratic National convention. That’s 2.5% of the total," he explained, noting that Sanders has amassed "one-43rd" of the delegates he will need and 47 more states need to vote.

BERNIE SANDERS' BIG NEVADA WIN PUTS SOCIALIST SENATOR IN DRIVER'S SEAT AS OTHERS SCRAMBLE

Sanders scored a decisive win in the Nevada Caucuses Saturday, tallying 46 percent of the vote with 50 percent of the results in -- a win that is worrying many members of the Democratic establishment that there may be no path to stop Sanders before the party's convention in July.

“Bernie’s got a lead, the field is splintered. He won Iowa with the lowest percentage of anybody in history and it ain’t even close. He won New Hampshire with the lowest percentage of the vote of anybody in history because the field is splintered," said Rove.

Former Vice President Joe Biden put a positive spin on his Nevada results and leaned on his supposed South Carolina firewall, where a majority African-American Democratic electorate still has him in the lead of the RealClearPolitics average of polls, with Sanders in a close second, billionaire Tom Steyer in third and Buttiegieg sitting in fourth place.

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Rove said that the South Carolina primary is a make-or-break contest for Biden. Rove also said that there is still a chance Biden can make a comeback if he wins South Carolina.

“He wins South Carolina, he goes into Super Tuesday with momentum. He loses South Carolina, he’s out of the contest,” Rove said.

Fox News’ Tyler Olson contributed to this report.