Keith Judd, a federal inmate convicted of extortion, captured 42 percent of the vote in Tuesday's primary. According to Democratic National Committee rules, the prisoner could qualify to assign at least one delegate to the national convention in Charlotte, N.C., this September.

Romney went on to note that polls showed more than 90 percent of Republicans were willing to vote for him, and said, with regard to the Obama administration, "people are recognizing it's been a disappointment."

President Obama also regularly polls above 90 percent among Democratic voters, although he has struggled in West Virginia, where conservative social politics and the dominant coal mining industry have made gaining traction difficult. Earlier this year, Gov. Earl Ray Tombin and U.S. Sen. Joe ManchinJoseph (Joe) ManchinGOP sees fresh opening with Dems’ single payer embrace Trump steps up courtship of Dems The Hill's 12:30 Report MORE — both Democrats — said they weren't sure whether they would vote for the president in November.