Democrat Richard Carmona is marking Election Day with the launch of his first TV ad.

Carmona is seeking the Democratic nomination in the race to replace U.S. Senator Jon Kyl, an Arizona Republican who announced earlier this year that he will retire upon completing his term. He is running unopposed in the primary.

Carmona's 30-second spot features an Army buddy explaining why the former Surgeon General should win the race in November.

Carmona will face the winner of the four-way Republican primary for U.S. Senate.

Arizona’s Senate race is garnering national attention because it is an open seat, a rarity for that body.