"If I didn't think I could win in November I wouldn't think about it," Thomspon said in an interview with Scott Baker for Breitbart.tv.
Thompson said he "had some thoughts" about when he might officially jump into the crowded field of Republican candidates, but he said he wasn't "ready to talk about that too much."
But, if he commits to running for president, Thompson said he will not do it halfway.
"I'm not interested in winning a primary and losing in November," he said in the Breitbart.tv interview. "I'm not interested in being the tallest midget in the room."
When asked about the Republicans who would be his competitors, Thompson would not go on the attack.
"Some of them I know very well, some of them I don't know well at all," he told Baker. "So I'm not going to pass judgment on them at all."
The former Senator did offer an example of what he thought voters were looking for in a candidate and weren't finding in Washington. Thompson also said voters might find what they were looking for in him.
"I think people are looking for someone that talks straight to them and deliver the news to them whether it's good or bad," Thompson said. "That's what I hope I bring to bear when people think of me in that context."
On one issue, Thompson seems to be in lockstep with the other Republicans in the presidential field.
Like the 10 leading Republican contenders did in a , Thompson has argued against leaving Iraq unless stability is restored. He noted that even when the U.S. leaves Iraq, the world still will be full of danger.
Thompson, speaking Friday night to the Lincoln Club of Orange County in California, sketched a broad agenda that hewed to Reaganesque themes — a strong military, a limited federal government and robust free markets.
Thompson also warned that people in the United States must be prepared to sacrifice in a world threatened by terrorism and hostile governments.
"Every generation has made sure that it did its part to make sure that it did endure, with the sacrifices they made. And now it's our turn," Thompson said.