“There could be a crime,” Blanche said in an interview on CNN’s “State of the Union.” He framed the central concern as whether voters might mistakenly choose the wrong Dan Sullivan and have their intended vote go unheard.

The Justice Department filed suit Thursday seeking to prevent Alaska officials from certifying election results if Republican Sen. Dan Sullivan loses. The department contends that including Dan J. Sullivan Jr. on the ballot is a deliberate effort to mislead voters.

Alaska’s Supreme Court ruled in June that both candidates could remain on the ballot. The four-candidate ranked-choice ballot identifies the incumbent as “Dan S. Sullivan,” a registered Republican, and labels him as the incumbent. The listing for Dan J. Sullivan Jr. does not include additional identifying information, according to the account of the ballot.

Blanche argued that states have a duty to prevent confusion in elections. CNN host Dana Bash pressed him on how the presence of two candidates with the same name violates the law. Blanche said the question was whether Alaska’s decision breached federal law or the Constitution.

The lawsuit faces a practical challenge: because ballots are secret, it may be difficult for the Justice Department to determine which Sullivan a voter intended to select. Blanche said there could be situations in which a voter’s choice makes the confusion apparent, but he did not explain how officials would establish that without compromising ballot secrecy.

Alaska Republican Sen. Lisa Murkowski, who is not on the ballot this year, called the lawsuit unnecessary. She said the state had already distinguished the candidates and that Alaskans did not need help choosing their preferred candidates. President Donald Trump criticized Murkowski after her comments and said the lawsuit had been his idea. Blanche declined to say whether Trump directed him to bring the case, citing his refusal to discuss communications with the president.

Democratic Sen. Adam Schiff of California said the Justice Department lacked standing to sue and warned that the case could be used to challenge election results. Blanche denied that the administration was trying to take over a state election, saying the state should be able to respond if confusion produces an improper result.

The dispute is unfolding as incumbent Sullivan faces former Democratic Rep. Mary Peltola in a closely watched race. The lawsuit could put Alaska’s election procedures and the limits of federal intervention under scrutiny, particularly if the result is close.