Maine has never been the most partisan state. Independents have long outnumbered Democrats or Republicans, and we have elected two governors who themselves were unenrolled.

But have we ever seen the major parties looking as weak as they do today? Ever since the surprise announcement that Sen. Olympia Snowe was retiring, there has been a wildfire of speculation about who would replace her.

The wildfire was doused when former independent Gov. Angus King announced that he was throwing his gargantuan name recognition and favorability ratings into the ring, and the most logical candidates from the Democratic side, U.S. Reps. Chellie Pingree and Mike Michaud, along with two-term Gov. John Baldacci, have all bowed out.

Pingree was very frank about the role King’s candidacy played in her decision. She said she did not want to be responsible for an outcome like the 2010 gubernatorial race, in which a Democrat and independent competed for the same pool of votes and Republican Paul LePage swept in with a plurality on Election Day.

(Pingree is married to Donald Sussman, who is buying an interest in MaineToday Media, the parent company of The Portland Press Herald, Maine Sunday Telegram, Kennebec Journal, the Morning Sentinel of Waterville and other related businesses.)

The point is not, as some Republicans charge, that King is really a Democrat. He’s not. The point is that the parties are having trouble coming up with candidates who can plausibly stake a claim to more than half the vote, regardless of who else is in the race.

Sens. Olympia Snowe and Susan Collins are the only major party candidates to get more than 50 percent of the vote in a statewide race since 1990. Neither party appears to have the candidates who can put that record to a test any time soon.

That’s too bad. For all the well-deserved criticism party politics attracts, these institutions play an important role in our system. Parties act as incubators of ideas and proposed policies, and they are the place where coalitions come together. Not everyone will like everything about a candidate, but a party’s nominee should be able to make a legitimate claim for the majority of the voters to win a mandate for action.

Narrow parties that are not built on broad coalitions create chaos, whether their candidate wins or loses.

The task for both parties should be not only winning an election, but also developing the kinds of candidates who can get more than half of the vote.