If America were dominated by old, white, election-denying Christians who didn't go to college, former President Trump would win the general election in as big of a landslide as his sweep of the first four GOP contests.

Why it matters: It's not. That's why some top Republicans are worried about the general election in November, despite Trump's back-to-back-to-back-to-back wins in Iowa, New Hampshire, Nevada and South Carolina.

Trump was declared the winner of Saturday's South Carolina's Republican Party the second that polls closed, trouncing Nikki Haley by 20 points (60% to 40%) in the state where she was governor.

• The Trump campaign declared the primary fight over, even though he can't officially clinch the nomination until next month.

By the numbers: Trump dominates with older white voters without college diplomas who believe the last election was rigged, according to network exit polls and AP VoteCast, which interviewed 2,440 South Carolina primary voters over five days.

Where he won: Two-thirds of Trump voters were white and didn't go to college. (VoteCast)

• Three-quarters of those without a college degree went for Trump. (CNN)
• 83% of "angry" voters backed Trump. (ABC)

Where he lost: 75% of Haley supporters correctly said Biden was legitimately elected president in 2020 (about 40% of them voted for Biden). (VoteCast)

• A stunning 62% of Republican primary voters said Biden wasn't legitimately elected. (NBC)

Those who went to the polls reflected Trump's strengths:

• This was the oldest South Carolina GOP electorate this century. (Chuck Todd)
• 60% of primary voters were white evangelical or born-again Christians. (CNN)

Reality check: That group isn't remotely big enough to win a presidential election. He would need to attract voters who are more diverse, more educated and believe his first loss was legit. South Carolina exit polls show he didn't do that.

• That's why Sen. Tim Scott of South Carolina, the Senate's only Black Republican, remains on Trump's short list for V.P.
• A bigger problem yet: Polls show these skeptics would be even less likely to swing his way if he's convicted of a crime — a real possibility among his four ongoing cases, insiders tell us.

The strategy: Trump's campaign says that in the battleground states where the election will be decided, his message will appeal far beyond the GOP base that propelled him to the nomination.

• "This is going to be a referendum against Joe Biden and his policies," a top Trump adviser tells us. "As long as Trump can tap into voter disillusion about the economy, out-of-control immigration, and more foreign entanglements, those are issues that affect people from all backgrounds."

Between the lines: Trump can't scare off swing voters as he works to scare them away from Biden by warning of bloodshed, tyranny, crime and violence if the president is re-elected.

• "For hardworking Americans, November 5th will be our new Liberation Day," Trump said yesterday at CPAC in National Harbor, Md.
• Trump called himself a "proud political dissident" in that speech, focused on the general election and never mentioned Haley.

"But for the liars and cheaters and fraudsters and censors and imposters who have commandeered our government, it will be Judgment Day."