Sen. Thom Tillis is following a simple formula for reelection in closely divided North Carolina: Stand with Donald Trump.

While some vulnerable Republicans have tried to hold the polarizing President at arm's length, Tillis boasts of Trump's endorsement for the 2020 elections.

That may have immediate political benefit as he fends off a March primary challenge. But it also comes with risks in North Carolina. As in other states, fast-growing cities and suburbs there have flashed warning signs for the GOP.

Tillis tells The Associated Press his re-election bid won't be about Trump's persona, but rather issues and accomplishments. His campaign believes they'll attract both the conservative base and independents.

But Meredith College professor David McLennan calls the election a "very touchy situation for Tillis to be in.''