PHOENIX (AP) -- Republican Jeff Flake and Democrat Richard Carmona will square off in a debate Wednesday in the race to fill the U.S. Senate seat being vacated by retiring Sen. Jon Kyl.
The one-hour debate produced by KAET-TV in Phoenix marks the first of three general-election debates between the candidates.
Flake is a six-term congressman who is known as a leader in the effort to do away with lawmakers' ability to designate federal dollars for local pet projects such as roads and bridges, or to help companies.
Carmona served as surgeon general under former President George W. Bush, a Republican. After the debate, former President Bill Clinton is scheduled to appear at a rally in Tempe for Carmona.
The race's outcome could determine whether the Senate is controlled by Democrats or Republicans. If the GOP picks up four Senate seats in the November elections, it would have a majority.
Flake has portrayed Carmona as a hand-picked rubber stamp for President Barack Obama. Democrats recruited Carmona, who until late last year was a registered independent, to run for Kyl's seat after it became clear that then-Rep. Gabrielle Giffords wouldn't run because of the head injuries she suffered during a shooting rampage. One of the recruiting pitches came from the president.
While Flake has had a presence on the airwaves, Carmona is still unknown to many voters.
One of the key issues in the race is the federal health care overhaul.
Flake voted against the Democratic-led effort to expand health insurance coverage and says he would vote to repeal it if he's elected. Carmona's campaign said he would not vote to repeal the law and would work to improve it.
Flake also supported a GOP budget authored by Rep. Paul Ryan that would change how future Medicare beneficiaries now under age 55 would get health care coverage. Ryan's plan would provide future seniors with subsidies to help buy a private health plan or buy coverage through a government-run program modeled after the current system.
Carmona said he opposes Ryan's plan because it transfers financial risks from the government to seniors. Seniors with chronic conditions such as diabetes, heart disease and high blood pressure will have difficulty getting coverage, Carmona says.
Carmona has proposed reducing health care costs for the elderly by focusing more on preventing diseases and by getting rid of more waste and fraud.
The two other debates are scheduled for Oct. 15 in Tucson and Oct. 25 in Yuma.