Americans often say they’re sick of the two-party structure of American politics, but independent candidates rarely get their support. This year, that might change ever-so-slightly. A number of candidates for governor and senator — such as Mufi Hannemann in Hawaii, Eliot Cutler in Maine, Greg Orman in Kansas and Larry Pressler in South Dakota — are running as neither Republican nor Democrat and could receive greater than 10 percent of the vote. The independent most likely to win is Alaska’s Bill Walker.

Walker, a former mayor of Valdez and 2010 candidate in the GOP gubernatorial primary, is teaming up with Democrat Byron Mallott, a former mayor of Juneau, to form a unity ticket against Republican Gov. Sean Parnell. What makes the pairing so interesting is that Mallott was running for governor as a Democrat, but he quit that bid to be Walker’s running mate. That means the state’s Democratic Party won’t be fielding its own ticket.

Can it work? Alaska isn’t friendly territory for non-incumbents taking on Republican candidates; no Democrat or independent has ever won a majority of the vote in a race for governor or senator against an elected incumbent Republican. The last time a Democrat or independent captured a majority of the vote in a race for an open seat or against an incumbent Republican who had not been elected (i.e. appointed or rising from lieutenant governor to take the place of a resigning governor) was in 1970. Walker is likely to need at least 50 percent of the vote to win because there are no major candidacies this year besides Parnell’s and his own.

On the other hand, independent and third-party candidates for governor have had more success in Alaska than elsewhere. Wally Hickel, a former Republican governor, won the 1990 gubernatorial race on a third-party ticket. Andrew Halcro, a former Republican member of the Alaska Legislature, took more than 9 percent of the vote as an independent in the 2006 race.

Recent polls indicate that the Walker-Mallott ticket has a decent shot at success. A Public Policy Polling (PPP) survey in late July showed Parnell leading Walker 41 percent to 40 percent. Two polls taken for Walker, an Ivan Moore Research poll in June and a Hays Research poll in late August, had him down to Parnell only 46 to 45 percent and ahead of Parnell 43 to 40 percent, respectively.

Are these polls accurate? There’s reason for caution. Often, internal polls, such as those taken for Walker, overstate the sponsor’s percentage of the vote. None of the polls assumed that Mallott would end up as Walker’s running mate. In the PPP poll, Walker pulled in 17 percent of the GOP vote in a matchup against Parnell. Will that hold now that he’s running with a Democrat? Meanwhile, Parnell was winning 25 percent of the Democratic vote in a matchup against Walker. Will that hold now that Walker’s running with a Democrat?

The race is too uncertain to call. As Josh Katz at The New York Times has said, Alaska has one of the worst polling error rates in the country. Just a few weeks ago, Joe Miller received nearly double the percentage of the vote that he polled for the Republican Senate primary.

For Walker to win, he’ll probably need to still be viewed as an independent. If he is seen as the de facto Democrat, he’ll probably lose. If he’s able to win a slice of the Republican vote and perform well among independents, he’ll have a good chance at victory.