Politics 2012: Voters winnow field in race to succeed Maine's Snowe Democrats and Republicans head to the polls Tuesday to select their parties' nominees to replace retiring Sen. Olympia Snowe, who said she was leaving Washington because the inter-party bickering was too much. Oct. 18 file photo. However, the perceived front-runner -- who's not on either party's ballot -- says he knows he has a bull's eye on his back and fully expects the eventual Democratic and Republican nominees to to come at him loaded for bear. "It's not easy being the target," former governor and Democrat-turned-Independent Angus King told The Portland Daily Sun in a recent interview. I'm prepared for that and I'll respond. After he vacated the governor's mansion, King said he intended to leave running for office behind -- until Snowe announced her retirement. "It was the manner in which Olympia Snowe retired," King told the Daily Sun. When she announced she wasn't seeking a fourth term, Snowe said she was frustrated by the "atmosphere of polarization and 'my way or the highway' ideologies has become pervasive in campaigns and in our governing institutions." As an independent, King says he's in a good position to address the gridlock in Washington. "I have a chance to make a difference in an institution that is just not functioning," he told the Daily Sun. "I believe there's an opening to make a difference," he said. His stint as governor proves "an Independent can function within a party system," he said. GMI Ratings Chief Executive Officer Rick Bennett, Tea Party-backed Scott D'Ambroise, Assistant Senate Majority Leader Debra Plowman, state Treasurer Bruce Poliquin, state Attorney General William Schneider and Secretary of State Charlie Summers are on the Republican ballot. Democratic candidates are Cape Elizabeth lawyer Cynthia Dill, state Rep. Matt Dunlap, Pollard Builders President Benjamin Pollard and Portland attorney, co-founder of Greenpeace USA and state Rep. Jon Hinck off on the Democratic ticket. There are good reasons for Democrats and Republicans to head to the polls next Tuesday, University of Maine professor Mark Brewer told SeaCoastOnline.com. Republicans have distinctive choices of moderates and conservatives while Democrats have candidates battling for statewide name recognition after congressional members Chellie Pingree and Mike Michaud and former Gov. John Baldacci declined to run once King announced. "This primary will tell us a lot about the fight in the GOP between the establishment wing and this Tea Party/Libertarian wing," Brewer said. For Democrats, "It does make you wonder, OK, the top tier all declined to run, so we're stuck with second-tier candidates," said Brewer, who called that label "unjustified." Observers in both parties told SeaCoastOnline.com they don't think King has the election sewn up, despite his perceived front-runner status. "Even though he's the front-runner now, it's not a done deal that he wins in the general," Brewer said.