Sen. Jon Kyl, the second-ranking Republican in the Senate, will not seek a fourth term in office, he said Thursday at a hotel in Phoenix.
Kyl offered no explanation for his decision to bow out other than simply being ready to end his tenure. "I really can't explain it any better than to say, my heart says it's time," Kyl said. "Let me hasten to say that there is nothing negative about the decision."
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Though not entirely unexpected, Kyl had not made public his plans. He has kept his decision private, only recently beginning to tell political allies. Kyl informed Gov. Jan Brewer of his decision late Wednesday, an Arizona Republican source said.
Kyl becomes the second Republican to announce his departure, following Sen. Kay Bailey Hutchison (R-TX). His decision will have an impact in the Senate, too, where Republicans will maneuver to fill leadership posts Kyl will vacate.
On Thursday, Senate Minority Leader Mitch McConnell said he would miss his top deputy.
"I think it is a big loss for the country," McConnell said. "But the good news is he'll be here for two more years helping us fight for the right things. We're going to miss Jon Kyl."
Kyl's departure will set off a scramble among Republicans who have long been eager to succeed him. At the top of that list is Rep. Jeff Flake, a six-term incumbent known for his ardent opposition to earmarks.
Flake has already laid the foundations for a potential bid. His campaign's finance committee met last week to plot strategy for his 2012 re-election bid, an effort that could easily morph into a statewide campaign. Flake is expected to make an announcement about his plans in the next few days, according to two sources.
In a statement, Flake praised Kyl's career in public service, calling Kyl "a tireless advocate" and a personal friend. "His retirement will create a huge void," Flake said. Flake did not mention his own potential candidacy.
But he won't be alone. Reps. Trent Franks, Dave Schweikert and Ben Quayle could all contemplate their own campaigns, and there is no shortage of Republican state legislators who have their eyes on higher office. Ex-Reps. John Shadegg and J.D. Hayworth are both expected to explore the race as well.
"It's probably going to be a pretty strong year fro Republicans. We have a very strong bench," Kyl said. He said he would not endorse any candidate in the GOP field "at least for a while. Maybe at some future point I will."
Democratic Rep. Gabrielle Giffords, recovering from an assassination attempt earlier this year, has long been seen as the party's best hope to win a statewide campaign. But Giffords' injuries remain severe, despite a seemingly rapid recovery, and she may not be able to run. Democrats could also turn to Homeland Security Secretary Janet Napolitano, though it's unclear whether the former Arizona governor would leave the administration to return to her state.
Other Democrats mentioned for the position include U.S. Attorney Dennis Burke and ex-Rep. Ann Kirkpatrick, who lost her seat in 2010.