While earmarks may form only a small percentage of the overall federal budget, DeMint said their impact is far greater because they symbolize the kind of backroom deal-making in politics that turns off many Americans.

"They always say, it's just a small amount of money, but earmarks always enlarge our budget and buy votes so that massive bills can go through," he said. Lawmakers can't advocate for spending cuts because "when we direct money back home through earmarks, it makes us complicit in the spending process. It's a killer."

DeMint, who is favored to win reelection against Democrat Alvin Greene, said he considered not running for reelection a year ago because of his frustration with his colleagues in Washington. Instead he started a political action committee to boost more conservative Republican Senate candidates including Rand PaulRandal (Rand) Howard PaulVaccine 'resisters' are a real problem Democrats fret as longshot candidates pull money, attention Journalist Dave Levinthal discusses 'uptick' in congressional stock trade violations MORE in Kentucky, Pat Toomey in Pennsylvania and Marco RubioMarco Antonio RubioSenate GOP campaign arm outraises Democratic counterpart in September House passes bills to secure telecommunications infrastructure Senators call for answers from US firm over reported use of forced Uyghur labor in China MORE in Florida.

When asked if there were any current GOP Senators who share his distaste for big government, DeMint could only think of one: conservative firebrand Tom CoburnThomas (Tom) Allen CoburnBiden and AOC's reckless spending plans are a threat to the planet NSF funding choice: Move forward or fall behind DHS establishes domestic terror unit within its intelligence office MORE (R-Okla.).

"Well, there's Coburn, who has got the courage to go out and make a scene on the floor or to stand up in a conference meeting and stand up to the appropriators. We don't have anyone else," DeMint said.