COLUMBIA — Newt Gingrich bid for an upset Saturday night in the South Carolina primary, the first Southern testing ground in the race for the Republican presidential nomination and historically a harbinger of the final outcome.

As polls closed across the state, exit polling showed the former House speaker ahead of former Massachusetts Gov. Mitt Romney overall, and leading by a wide margin among the state’s conservatives, tea party supporters and born-again Christians.

Romney held a small advantage among moderate and liberal voters.