NEVADA, Iowa, Oct. 3 — Twenty-four minutes after he began speaking in a small restaurant the other day, Fred D. Thompson brought his remarks to a close with a nod of his head and an expression of thanks to Iowans for allowing him to “give my thoughts about some things.”

Then he stood face to face with a silent audience.

“Can I have a round of applause?” Mr. Thompson said, drawing a rustle of clapping and some laughter.

“Well, I had to drag that out of you,” he said.

Mr. Thompson is a former United States senator, television actor and Watergate investigator. His entry into the presidential race was highly anticipated by many Republicans, who saw or hoped to see in him outsized political talent and a commitment to conservatism that would enliven a Republican field that many found lacking.

But as Mr. Thompson campaigned across Iowa this week, he was something other than the dynamic presence that some in his party have been yearning for. Iowans saw a candidate who is subdued and sonorous, a laconic presence who spoke in soft monotone, threw few elbows and displayed little drive to distinguish himself from his opponents.