Republican businessman Matt Bevin was elected Kentucky's next governor on Tuesday in a setback for Democrats who had controlled the governor's mansion in every election but one since 1971.

Bevin, who rode Tea Party support to a narrow victory in a four-way Republican primary, defeated State Attorney General Jack Conway, who quickly conceded on Tuesday night after his late October lead in the polls evaporated on election day.

The partisan divides seen nationally over gay marriage and President Barack Obama's signature healthcare law dominated the hotly contested race in Kentucky to replace Democratic Governor Steve Beshear, who cannot run because of term limits.

Bevin's path to victory included courting religious conservatives after meeting with embattled Rowan County Clerk Kim Davis after she was jailed for defying a federal judge's order to issue marriage licenses to gay couples.

He also benefited from a late infusion of cash from national Republicans, with the Republican Governors Association pouring $2.5 million into the state during the final two weeks of the campaign. The organization said it spent $6 million total on the Kentucky governor's race.

Bevin had pledged to roll back the expansion of Medicaid to provide health coverage to the poor under Obama's health plan as started by the current governor, which Conway had supported.

Although Kentucky voters routinely send Republicans to Washington, D.C., experts thought Conway had the advantage going into election day given Democrats' state-level strength. Only one Republican had been elected governor in Kentucky since 1971.

Bevin's lieutenant governor, Jenean Hampton, becomes the first African American elected to statewide office in Kentucky.

Meanwhile, Republicans were expected to score another victory in Mississippi, where incumbent Governor Phil Bryant was favored to win a second term. Results were not yet known.