The darling of conservatives is quick to rebut the perception that he spends his time traveling the country promoting candidates, saying that's largely done through the Web or in interviews near his Washington office.
Still, he says his work through the Senate Conservatives Fund is a necessary part of his fight against federal spending, borrowing and the growing budget deficit. By last week, his fund had contributed more than $1 million to anti-establishment candidates running this year.
"The only way I can do the things I've promised South Carolinians is to help bring more people into the Congress that think like we do," said DeMint, a 58-year-old father of four and grandfather of two. He lives in Greenville and insists he spends at least three days in the state each week.
For his own race, DeMint has amassed $5.9 million over the past six years, using some to pay off past campaign debt and on fundraising expenses. On Thursday, he had $3.5 million available.
That compares with zero raised by his June 8 primary opponent, Susan Gaddy, whom DeMint says he's never met. Though he says "any opponent is serious," DeMint has yet to run a TV ad for his primary race.
The winner will face one of two Democratic challengers: former legislator and judge Vic Rawl, 64, of Charleston, who has amassed $185,000 since announcing in March, and unemployed veteran Alvin Greene, 32, of Manning, who hasn't raised a penny.
Gaddy's name will be largely unknown at the ballot box. She has no signs, no Web site and doesn't send e-mail. She said her method of educating voters is through churches, colleagues and cousins.
"It's old-fashioned, but so much more fun," said the 47-year-old Charleston lawyer, who insists she's in the race to win. "It's fabulous. Everybody's so friendly."
Gaddy, a former Democratic precinct president, volunteered and voted for President Obama in 2008 but says her disappointment in him and his administration made her change parties. Gaddy insists she shares DeMint's views on issues.
"I keep trying to find ideological differences, because it would be helpful to me," she said.
Only Rawl is deemed by the Democratic Party to be a serious candidate.