ST. PETERSBURG — Citing fatigue with a brand of politics in the Legislature that he says has left him feeling powerless, state Rep. Rick Kriseman announced Monday that he won't seek re-election this year."I've been in office for 12 years, the last six in Tallahassee, and it's been extremely challenging and frustrating being up there fighting a system that I think is broken," said Kriseman, a Democrat. "It's time to come home and focus on my family and law practice, and figure out what is next for me in politics."In calling quits to a legislative career that started in 2006, Kriseman left open the possibility he might run for various other public offices, namely state Senate, the Pinellas County Commission, the U.S. Congress, supervisor of elections or St. Petersburg mayor.It's that last one, now occupied by Bill Foster, that comes up for re-election next year — the timing of which makes it most likely that it would be the first office Kriseman would consider."The mayor had his share of challenges," said Kriseman, who served with Foster on the eight-member City Council from 2000 to 2005. "I would do it differently, just as he would do it differently if he served in the state House."Although the mayor's race is 18 months away, it's not too soon for Foster's challengers to emerge, said Herb Polson, who replaced Kriseman on the council and is now retired."It's time for candidates to put feelers out there," Polson said. "And Rick is certainly knowledgeable on city politics. He was a colleague of Bill Foster's. They know each other very well. He's not just another candidate."Kriseman, 49, said his decision to quit the state House wasn't influenced by the redrawing of his district's boundaries. Once favoring Democrats by 6 to 7 percentage points, it now skews Republican. But it also includes six homeowners associations that were in his old City Council district and beach communities that he said would support him because of his strong beach-restoration advocacy during the BP oil spill and a push to get the online travel-booking service Expedia to pay more in taxes.While he won't leave office until November, his announcement should set off a scramble for a vacant seat for what is now District 69. Two Republicans have already filed. Jim Dobyns has raised $1,050 through March. Kathleen Peters has raised $10,115. Josh Shulman, a financial planner with Wells Fargo, said Monday he is filing to run as a Democrat today.The job pays $29,000.His departure leaves state Rep. Darryl Rouson as the lone Democrat in the Pinellas delegation."I'm in shock," Rouson said. "I knew he was thinking about it. But I fully expected that, with his voice and passion, he'd be returning."Kriseman said it'll take a few months to determine what's next."It's a matter of taking some time off, clearing my head," he said.If a letter he posted on his website Monday is any indication, Kriseman has the city on his mind. While downbeat about the current state of Tallahassee, the letter is sanguine about his experience in city politics."On the City Council, ideas were valued," he said. "In our state Capitol, and especially in the House under the rule of Speaker Dean Cannon, politics trumps policy."He's already voiced strong opinions on city issues. When Foster decided to scrap a $64 million police station project last month, Kriseman tweeted that city officials should find the money to build it — even if it comes at the expense of a new pier."A station should take precedence over a pier," he stated. Since St. Petersburg has switched to a strong mayor form of government, an incumbent hasn't lost. But it's a short history, with David Fischer in 1997 and Rick Baker in 2005. While Baker easily won re-election with a resounding 70 percent of the vote, Fischer struggled, losing the primary before beating back his challenger in the general election by 6 percentage points.Only Foster and longshot candidate Paul Congemi have stated they are running in 2013. City Council Chairwoman Leslie Curran said she'll "make a decision in due time." Her colleague, Jeff Danner, won't comment on speculation he might run. Rick Baker said in March that he's not considering a run. Former mayoral candidate Scott Wagman said he's open to it. Kathleen Ford and Deveron Gibbons, who ran and lost against Foster in 2009, are mentioned, as well, but couldn't be reached."Rick has been a council member, which immediately lends credence to him running," Wagman said. "If Kathleen Ford and Rick Baker jump in, I'll jump in again just to muck it up."