A Combative Thompson Sways Voters
Joshua Lott for The New York Times
Fred D. Thompson greeted bystanders
on Friday at a campaign stop
in Summerville, S.C.

MYRTLE BEACH, S.C. — John and Ann Berenberk dutifully watched the umpteenth Republican presidential debate on television on Thursday night and had an epiphany. It was about the candidate they had previously referred to as the tall, silent one. Fred D. Thompson.

The last of the candidates to enter the race, Mr. Thompson, 65, a former Tennessee senator, has so far seemed to distinguish himself mainly by a laconic style that has made him almost invisible beside the others on the stage in past debates, the Berenberks said.

“But then last night — we hadn’t even been thinking about him — all of a sudden it was clear he was the one,â€