It depends on her health, of course, but Tucson shooting victim Rep. Giffords, who expressed an interest in running for the senate prior to the tragedy, may represent the Democrat's best chance to pick up a senate seat in 2012.

Politico:

The race for Arizona's open Senate seat has quickly focused in on one question: What will Gabrielle Giffords do?

The Democratic congresswoman, who survived an assassination attempt in Tucson last month, is still undergoing rehabilitation in Houston for a gunshot wound to the head. Physicians have warned that her recovery will proceed at its own pace.

[...]

Giffords was mentioned as one possible contender for the 2012 race during a closed-door meeting of Senate Democrats on Thursday, two sources with knowledge of the meeting said.

In Arizona, strategists continue to view Giffords as a compelling candidate for higher office. That's a distinction few Democrats in the state can claim after last November, when Republicans captured two U.S. House seats and won every statewide office on the ballot.

"Congresswoman Giffords's name was clearly at the top of the list of potential candidates against Sen. Kyl, or if Sen. Kyl stepped down, over the past couple years. Given that, a lot of people of course thought immediately of her for this seat," Arizona Democratic Party Chairman Andrei Cherny said.