Three individuals named Dan Sullivan have become central figures in Alaska's U.S. Senate race, creating an unusual dynamic ahead of the November general election.

Former Anchorage Mayor Dan A. Sullivan, a Republican, endorsed incumbent GOP Sen. Dan S. Sullivan last week. The endorsement came as the senator prepares for the general election following the Aug. 18 top-four primary.

The race also features Dan J. Sullivan, a retired teacher from Petersburg who ran as a Republican but appeared on the primary ballot as Daniel J. Sullivan Jr. without party affiliation. He received about 2.4 percent of the vote.

Republicans have accused Dan J. Sullivan of running to confuse voters and siphon support from the incumbent in a race viewed as competitive for control of the Senate. Democrats and the challenger have denied any coordination.

Incumbent Sen. Dan S. Sullivan and Democratic former Rep. Mary Peltola advanced from the primary as the top two finishers. The open primary under ranked-choice voting sent the top four candidates to the general election.

The name similarity has drawn national attention, with legal battles earlier this year over ballot access for the challenger. A judge and later the Alaska Supreme Court allowed Dan J. Sullivan to remain on the ballot despite initial disqualification attempts by state election officials.

Sen. Sullivan is seeking a third term in the Republican-leaning state. The contest pits him against Peltola in what analysts consider one of the closer Senate races this cycle.