Both Mitchell and Giffords ran their races emphasizing "comprehensive immigration reform"–reforms similar to what passed in the Senate this year, including both a guest-worker plan and strengthened border security–in a state where immigration is a crucial issue. Mitchell in particular took pains to fend off Hayworth's attacks on his border credentials by emphasizing he favored the kind of reforms endorsed by Arizona Gov. Janet Napolitano and Sen. John McCain, a Republican. Giffords, running in a border district, was attacked in television ads paid for by the Minuteman PAC.

Hayworth's dramatic loss will probably be heralded as a surprise this election: He represented an affluent suburban Phoenix district, largely immune from economic challenges. He'd won comfortably in the past–getting 60 percent or more of the vote in 2000, 2002, and 2004. Hayworth is author of Whatever It Takes, a book on the "immigration invasion," as he calls it. Some reports tied him to disgraced lobbyist Jack Abramoff.

Other Republicans who have taken pains to emphasize conservative immigration stances–most notably Sen. Rick Santorum of Pennsylvania–found the issue failed to give them a much-desired election bounce.