A trio of Senate races in the Southwest may end up determining whether Republicans or Democrats control the body following the November election, setting up fierce battles that could carry national consequences.
Though the outcomes of the match-ups in Arizona, Nevada and New Mexico hinge mostly on the individual candidates and local political landscape, presidential politics will play a role as well, experts say. Because of growing Hispanic populations and proximity to the border, immigration has emerged as a hot-button issue in all three states.
Republicans are the slight favorites to win in the race for retiring Republican Sen. Jon Kyl's seat. Of the three states, Arizona's electorate is the most conservative and the immigration debate has long been a galvanizing issue for the GOP. The state's recently passed controversial law allowing officers to request proof of U.S. citizenship from people they suspect might be illegal immigrants will receive Supreme Court scrutiny in the coming weeks.
Though still facing primary competition, Rep. Jeff Flake is expected to be the GOP standard-bearer. A fiscal conservative, Flake has served in the House since 2001.
The biggest x-factor in this contest is likely Democratic nominee Richard Carmona. Carmona, a Vietnam veteran and physician, served as Surgeon General under President George W. Bush. His compelling life story and background working in a Republican administration make him one of the few Democrats who could pull off an upset.
The key to Arizona may just be how hard the Obama campaign tries to compete in the state. Obama lost to Republican nominee Sen. John McCain, who hails from Arizona, by 8.5 percent in 2008, but the campaign has signaled it might invest some resources in the state thanks to the increasing Latino population.
"There are demographic changes going on there but it's still a pretty Republican state," says Kyle Kondik, a political analyst at the University of Virginia's Center for Politics. "Carmona's got this good profile, this good back story but I think Flake is going to be awfully hard to beat and I think some of it depends on the national Democratic-Obama machine. How much they decide to play in Arizona might have some impact there."
If the Republicans have an edge in Arizona, the Democrats have the same in New Mexico in the bid to replace retiring Democratic Sen. Jeff Bingaman. There, the likely match-up pits Rep. Martin Heinrich, a Democrat, and former Rep. Heather Wilson, a Republican, against each other.
"I suspect that Obama will do pretty well in New Mexico, which means that Wilson will have to run several points ahead of Romney, if he's the nominee, and that's asking a bit much," Kondik says.
Obama won New Mexico by 15 points in 2008.
While Wilson has a reputation as a moderate in a blue state, it may not be enough for her to beat Heinrich.
Jennifer Duffy, senior editor for the Cook Political Report, says Wilson is running a strong campaign but she and Heinrich will be fighting for the same votes.
"She's a really strong candidate, she's not too conservative for that state and she's running one of the better campaigns that I think we've seen awhile," she says. "But they basically share a base. So it becomes who is more successful getting outside of Albuquerque and appealing to voters there."
While all three races are expected to be close, Nevada is the biggest nail-biter of them all. Similar to New Mexico, it features two sitting members of Congress against each other – Democratic Rep. Shelley Berkley and Republican Sen. Dean Heller. Heller, a former congressman, was recently appointed to the Senate to replace Republican Sen. John Ensign, who resigned amid controversy.
Corrected on 4/09/2012: A previous version of this story stated Rep. Heather Wilson is a member of Congress. She left office in 2009.