Dan J. Sullivan, a retired teacher challenging incumbent Republican Senator Dan S. Sullivan of Alaska, secured a spot on the general-election ballot after a contested primary, according to The Associated Press.

His emergence creates a potential voting headache for the incumbent, as Republicans fear voter confusion between the two Sullivans could benefit Democratic challenger Mary Peltola. Dan J. Sullivan won just a few thousand votes, and it took nearly a week for his advancement to be confirmed.

Alaska uses a ranked-choice voting system, adding further uncertainty to how voters will navigate the ballot. Senator Sullivan trailed Peltola by nearly six percentage points in the nonpartisan primary. Democrats view Alaska as a key target in the midterms, where control of the Senate is at stake.

The Alaska Division of Elections initially removed Dan J. Sullivan from the ballot, citing concerns about voter confusion, but an Alaska judge restored his candidacy, ruling the agency had overstepped. Republicans allege coordination with the Peltola campaign, which denies any involvement.

Dan J. Sullivan maintains he is running in good faith. The race remains one of the most competitive in the country, with Democrats needing to flip four seats to gain control.