DeMint has made headlines in several GOP primaries this cycle. He was an early supporter of Florida Senate candidate Marco RubioMarco RubioRepublicans play clean up on Trump's foreign policy Top Dem: GOP is terrified of Trump McConnell on Trump: 'I'm not a fan of the daily tweets' MORE (R) -- he introduced him at the recent CPAC conference in Washington -- and backed conservative state Assemblyman Chuck DeVore (R) in California. He also toyed with the idea of backing developer Patrick Hughes's primary challenge to now-Illinois GOP Senate nominee Mark KirkMark KirkThe Hill's 12:30 Report Trump, judges on collision course GOP senator: Don't link Planned Parenthood to ObamaCare repeal MORE.

DeMint's support has become a counter-weight to Sen. John McCainJohn McCainTHE MEMO: Trump's wild first month Trump’s feud with the press in the spotlight Republicans play clean up on Trump's foreign policy MORE (R-Ariz.), who is backing Republican Carly Fiorina in California and Norton in Colorado. McCain also backed Kirk in Illinois and he has supported Florida Gov. Charlie Crist (R) in the past.