The race for the seat of retiring Maine GOP Sen. Olympia Snowe has emerged as perhaps the most critical – and unpredictable – Senate contest in 2012.
Having a crowded field of six Republicans, four Democrats and two independents for the June primary was complicated enough. But former Gov. Angus King -- an independent who has yet to say how he will caucus -- jumping into the race has even top political analysts guessing about the outcome.
"After 28 years of watching some 950 Senate contests, it has been years since we have encountered anything truly new or even surprising. That is, until this open seat in Maine," Jennifer Duffy, senior editor for Cook Political Report, writes.
"There were 33 Senate contests on the ballot this cycle. With this now open seat, it has become 32 Senate races and a silent auction. How do we (predict) a race in which the front runner won't declare a party?"
King already appears to be the favorite, taking 56 percent of the vote against the top Democratic and Republican candidates, according to a poll released Friday by the liberal-leaning Maine People's Resource Center.
Republicans need to gain at least three seats to take control of the U.S. Senate for the first time since 2006. And with most political handicappers saying the GOP has about an even chance, King's decision to vote with either Democrats or Republicans could make him "the most powerful player in American politics," Duffy said.
What King will do is unclear because he is not saying. But the GOP is already on the offensive.
"Independent Angus King?" asks a voice in a National Republican Senatorial Committee video.
"But who dragged him into the race. Chuck Schumer and the Democrats … to ensure King would caucus with Democrats."
King dismissed the accusation as "bunk." "If I said I'm going to caucus with the Democrats or with the Republicans, I'd be giving the game away," he told a local TV station.
The Democratic Senatorial Campaign Committee has said very little about King and did not respond to a request for comment.
The NRSC and King's campaign also did not return messages. Meanwhile, voters have been left to cull King's legislative record to help them decide how he might caucus or even if they'll vote on such a wild card candidate. King, a Dartmouth College and University of Virginia School of Law graduate, endorsed George W. Bush in 2000, then Barack Obama is 2008.
Though King recently said he supports health care reform and opposes a repeal, he thinks entitlement reform is needed to balance the federal budget, Duffy notes. King was twice elected governor, winning as an independent first in 1994 with 35 percent of the vote in a race that featured then-GOP state deputy Treasure Sue Collins, Maine's other senator.
King won reelection four years later with 59 percent of the vote. The top Democratic candidates in the race appear to be state Sen. Cynthia Dill and former Secretary of State Matt Dunlap, who are in a statistical tie for the lead.
Secretary of State Charlie Summers has a roughly 24-point lead on all other GOP candidates, according to the poll released last week of roughly 1,000 likely Maine voters, who largely remain undecided.