Asecond Idaho poll – this one by Greg Smith, for KTVB-TV and the Idaho Business Review, shows almost exactly what last week’s Mason Dixon did. About the only thing different was the degree of the most important factor: The undecided.

A surface reading in the governor’s race shows Democrat Jerry Brady leading Republican Butch Otter, 41% to 36%; and in the 1st congressional district, it shows Democrat Larry Grant leading Republican Bill Sali, 38% to 34%. The closeness is absolutely startling; these figures, reflecting last week’s poll (and following up in some ways from Smith’s last poll in August) are unusual, different for Idaho than any polling result in the last dozen years.

And yet you’d be mistaken to shorthand these results as suggesting a probable razor-close finish. What’s more likely is that one side or the other will win decisively. We just don’t know which.

During those dozen years, since Idaho politics has been frozen in place – almost everything went to conservative Republicans, usually by big margins. Our observation during that time has been that matters would eventually change; politics does not remain static forever. When that change would come, has always been less clear.

Is this the year – in this year of failed local Republican candidacies against a backdrop of larger national Republican failures – the year of the Big Melt?

There’s no perfect answer, because that depends on a good many Idaho people who haven’t yet decided what to do about these races. In the governor’s race, 20% of the voters call themselves undecided between Otter and Brady, and in the congressional, 25% between Sali and Grant. Those are unusually big undecided numbers for so late – this poll was conducted this week – in a campaign.

What they will do, we don’t know. But the similar opinion patterns suggest that many of the same factors are causing that indecision; and we know that historically, late undecideds tend to break strongly one way or another, often because of some factor emerging in the last few days before an election.

Add the bulk of the 20% to either Otter’s or Brady’s numbers, for example, and you wind up with a big win – which, right now, seems more likely than a super-close result.

The catch is that there’s almost no way to know – now – which way they will go.

Three quick quotes along these lines.

Jim Weatherby, retired professor at Boise State University, and a frequent pundit for KTVB, on the governor’s race: “At this point, it’s just a matter of each group getting their voters out. It appears that Brady has his base, the question is, can Otter get his base and some independents to close the gap?”

A take from McJoan, on the front page of the Daily Kos blog: “My gut feeling is that the huge number of undecideds is comprised of Republicans that just don’t know if they can bring themselves to vote for a Dem, or if they’ll just stay home. There’s also been tremendous growth in the district in the last few years, and while some of these people might generally trend Republican, they don’t have any allegiance to Otter and have to see Sali for the nut job he is.”

And from Idaho Statesman columnist Dan Popkey, after interviewing voters at Canyon County yesterday (and before the new poll results): “In the final days of the campaign, Sali must win back the loyalty of undecideds” if he is to win.

They and others all say pretty much the same thing: A lot of people who have been voting for Republicans are torn this year. They’re having a lot of trouble deciding.

When they do, they will either keep Idaho in its decade-plus one-party status, or open the doors to genuine two-party competition with two big Democratic wins (at least – and maybe a string of others down-ticket).

Either outcome is plausible; what’s hardest to imagine, right now, is something in between.