If you can believe it, this is only the second poll all year in which Matt Rosendale has led Tester by any margin. (A Republican pollster had him up by two points in late August.) Not only that, some of Tester’s leads lately have been gory. The Harris Interactive/Scott Rasmussen poll has put ahead consistently by 6-7 points over the last few days and two other polls taken in mid-October had him ahead by 9-10(!).

Which means Change Research, the pollster responsible for this new data, will either be embarrassed tomorrow night or have bragging rights over other Montana pollsters for years to come.

If their name sounds familiar, by the way, it’s because they’re the same firm that proclaimed a dead heat between Ted Cruz and Beto O’Rourke in Texas yesterday. Change Research is out on a lot of limbs right now.

Montana is nearly 18 points more Republican than the country overall, per Nate Silver’s site. Ousting incumbents is always hard but it shouldn’t be this hard in this state with this economy.

If you’re thinking big picture, a Rosendale upset would be huge in offsetting Democratic pick-ups in Nevada and Arizona, both of which look to be more likely than not right now. At last check the early voting in Nevada appeared daunting for Dean Heller — not impossibly so, but enough to make Democrat Jacky Rosen the favorite tomorrow. Meanwhile, although the Arizona polling has been topsy-turvy for a week, there seems to be a late break towards Democrat Kyrsten Sinema. For instance, OH Predictive Insights has Martha McSally up a point in a new survey released today but that firm had had McSally up 6-7 points in its last two polls. Similarly, Harris/Rasmussen has McSally up 2.1 points today … after showing her ahead by nearly seven on Friday. And those are the best polls available for the Republican. Other recent surveys have Sinema winning by anywhere from three points to six.

The half-glass-full view of all that is that even if Nevada and Arizona flip to blue, the GOP’s about to flip North Dakota to red and maaaaaybe steal Tester’s seat. Democrats could hold on to all of their battleground seats in red states, then, and Republicans would still have a 51/49 advantage in the Senate last year. The glass-half-empty view is that Democrats flipping Nevada and Arizona would be ominous insofar as both states are must-win for them to have any chance at a Senate majority and that late breaks towards Rosen and Sinema might signal a national blue wave. If that happens and Democrats hold all of their battleground seats (except North Dakota) then suddenly the Senate is hanging by a thread in Texas and Tennessee. If either Cruz or Blackburn is upset, Schumer controls the Senate. Even if they both hold on, we’d be staring at a 50/50 chamber next year. Lisa Murkowski would have veto power over everything, including Supreme Court nominees.

Oh, and if you’re wondering if there are any longshot blue-state seats that are ripe for a Republican upset, probably not. The one obvious one was Sleazy Bob Menendez in New Jersey, but the polls this morning suggest that Democrats have come home. Quinnipiac:

Change Research:

Needless to say, the more likely it is that Rosen and Sinema are surfing a blue wave, the more likely it is that Menendez wins easily. An upset in New Jersey would require everything to work against the incumbent. High national turnout by Democrats would ruin that perfect storm for Hugin.