Updated: 12:49 p.m.

Sen. Jon Kyl’s decision to retire in 2012 could ignite a succession scramble, both on Capitol Hill within the GOP leadership team and in Arizona among Republicans who have their eye on higher office.

Rep. Jeff Flake (R-Ariz.) is expected to announce a Senate bid, perhaps within days, according to a knowledgeable Republican source. “An announcement is coming in a few days and there’s a strong likelihood that he will run,” this source said. According to a Democratic House aide, Rep. Gabrielle Giffords (D-Ariz.) would have almost certainly been a candidate as well prior to last month’s shootings in Tucson. 

In Washington, a trio of top Republican Senators may angle for Kyl’s Minority Whip slot. The No. 2 position in the Senate Republican leadership could become the Majority Whip position in 2013 depending on the outcome of the 2012 elections, and National Republican Senatorial Committee Chairman John Cornyn (Texas) and Policy Committee Chairman John Thune (S.D.) are expected to consider running for it.

Sen. Lamar Alexander (R-Tenn.), who currently holds the No. 3 spot in leadership, plans to run for the Whip job, an aide said Thursday.

Kyl’s announcement and the opportunity to move up in leadership could also affect Thune’s decision on whether to run for president. That decision is expected by month’s end. Kyl’s exit could also open the door for other ambitious Republicans to enter the leadership ranks. Some of the initial names on that list include Sens. Mike Johanns (Neb.), Kelly Ayotte (N.H.) and Rob Portman (Ohio), among other freshmen.

Cornyn will clearly be looking for another leadership position for the 113th Congress, given he is in the midst of his second consecutive cycle as NRSC chairman and is up for re-election in 2014. Some Republican Senate aides have said he could have an edge in any leadership contest if the GOP retakes the majority in 2012. 

Alexander has a network of strong relationships through the GOP Conference and could prove formidable should he run. 

And Thune is strong with Senate GOP conservatives and could pose a strong challenge for Whip.

In Arizona, Democrats now see Kyl’s seat as a prime pickup opportunity in an otherwise challenging 2012 cycle. The Democrats ran strong in the Grand Canyon State in the 2006 and 2008 cycles, with the pendulum swinging back toward the GOP in 2010. Sen. John McCain (R) won re-election by a wide margin in November, and the Republican brand is again strong in the state.
 
“Sen. Kyl’s announcement has instantaneously catapulted Arizona to a prime pickup opportunity for Senate Democrats this cycle,” Democratic Senatorial Campaign Committee spokesman Eric Schultz said.
 
Flake, meanwhile, is considered among the GOP’s top potential recruits.

He dominated his Democratic opponent by nearly 40 points in the 2010 cycle to capture his sixth House term, and he’s sitting on more than $627,000 in his campaign account. That’s hardly enough to fund a competitive Senate contest, but it certainly gives him a head start on other prospective candidates.

Just minutes after news of Kyl’s departure had been confirmed, the fiscally conservative Club for Growth’s political action committee jumped on the Flake bandwagon.

“Run, Jeff, run!” Club President Chris Chocola said in a statement. “Jeff Flake has a 100 percent lifetime score on the Club for Growth’s Congressional Score Card, and is one of America’s most vocal champions for limited government and economic liberty. He is the perfect successor to Jon Kyl in the Senate, and Club for Growth PAC strongly encourages him to run for the seat.”

Term-limited Gov. Jan Brewer could be another Republican to watch in the coming months. She cruised to victory in November and was part of a GOP sweep at the polls. Arizona Republicans captured every statewide office, including secretary of state, attorney general, state treasurer and even education superintendent.

Failed 2010 Senate candidate former Rep. J.D. Hayworth has also been mentioned as a potential candidate.

Regardless of the shape of the field, Cornyn said he was “confident that this seat will remain in Republican hands.”

“It’s clear that no matter who the Democrats nominate, that person will find it very hard to sell voters on the Democrats’ agenda of reckless spending in Washington and their failure to create jobs while driving our national debt past $14 trillion,” the Texas Republican said.

Nevertheless, Democrats see good news in Kyl’s departure, particularly since they are facing a 2012 cycle where they will be playing far more defense than offense in Senate campaigns. The GOP has just 10 seats up for re-election compared with 23 for Democrats.

But Schultz of the DSCC said Kyl’s retirement, combined with that of Sen. Kay Bailey Hutchison (R-Texas), former Sen. Jim Talent’s (R) reluctance to run against Sen. Claire McCaskill (D-Mo.) and “the ongoing Republican civil war are four early signals that 2012 will be full of surprises and that Democrats will ultimately do well next November.”

“Republicans now likely face a primary in Arizona, similar to impending free-for-alls in nearly every other state,” Schultz said. “Time after time, Republicans nominated unelectable candidates — and they look willing to do so again this cycle.”

Democrats likely to be in the mix for Kyl’s seat include Homeland Security Secretary and former Gov. Janet Napolitano. Napolitano was a popular governor before resigning to take a post in President Barack Obama’s Cabinet. U.S. attorney Dennis Burke and former Rep. Ann Kirkpatrick are also people to watch.

Depending on the progress of her recovery, Giffords could be part of the conversation. She originally advanced to Congress by winning the open Republican-leaning 8th district in 2006, and she survived a tough challenge in 2010.

She was thought to be a rising star among Arizona Democrats before she was shot in the head while meeting with constituents last month. She is slowly recovering from the attack, and aides reported this week that she has begun speaking again.

Jessica Brady contributed to this report.