PHOENIX (AP) — Ruben Gallego and Kari Lake meet Wednesday for the only debate of the Arizona Senate race, a matchup that comes as voters begin casting ballots in a contest that will help determine control of the U.S. Senate.

Lake, a well-known former television news anchor and a darling of the populist right, has tried but struggled to redefine herself since losing the 2022 race for governor.

Gallego, a Democratic congressman representing largely Latino areas of Phoenix, has used his financial advantage over Lake to run ads playing up his military service and up-by-the-bootstraps personal story rather than his progressive record in Congress.

The debate, which will air live on most television stations across the state at 9 p.m. EDT, presents Lake with a chance to reset a race where polls and observers suggest she's modestly trailing. For Gallego, it's an opportunity to introduce himself to voters who still don't know him.

Both candidates are working to win over a small share of Republicans and conservative independents who are open to splitting their vote between the parties. This group has been instrumental in the rise of Democrats in Arizona, which has transitioned from a Republican stronghold to a battleground state over the past decade.

They've fought to focus voters on the territory most favorable to them.

For Gallego, that's abortion rights after a state Supreme Court ruling outlawed virtually all abortions until the Legislature rolled it back to 15 weeks. Lake has spoken favorably of stricter limits.

Lake prefers to talk about the U.S.-Mexico border. She paints a dire picture of drug and human trafficking, and she links Gallego to record border crossings and scenes of disorder during President Joe Biden's administration. She highlights his prior comments critical of a border wall.

Lake is an unflinching supporter of former President Donald Trump and his lie that he lost the 2020 election because of fraud. She has never conceded she lost her own 2022 race for governor, and continued to fight the outcome in court even after launching her Senate campaign. Separately, she's tried and failed to convince courts, including the U.S. Supreme Court earlier this year, to outlaw the use of electronic voting machines.

She's also highlighted Ruben Gallego's 2016 divorce from Kate Gallego, who is now the mayor of Phoenix. Noting the marriage ended weeks before the couple's son was born, Lake says Gallego abandoned his wife while she was pregnant. Kate Gallego has endorsed her ex-husband and campaigned with him as recently as last week.

Gallego is a military veteran who has served in Congress for a decade.

The son of immigrants from Mexico and Colombia, he was raised in Chicago by a single mother and eventually accepted to Harvard University. He enlisted in the U.S. Marine Corps Reserve while he was on a break from Harvard. He fought in Iraq in 2005 in a unit that sustained heavy casualties, including the death of his best friend.