Not much changed from the last map. I see almost no way that the Republicans could gain enough seats to regain the Senate: perhaps if the polls are misreading the races in Indiana and Missouri, where individuals may feel ashamed to admit a vote for Akin or Mourdock, there could be enough upsets for the Republicans to win, but I don't expect this to happen.

Montana: This is unquestionably my least confident state. Montana tends to have a Republican lean most years, but it also has a notable moderate streak, something that works well for Tester. The fact that he isn't hitting 50% in any of the polling there worries me, but his lead has looked fairly consistent of late.

The only lead change from my last map is in North Dakota. While I think Heidi Heitkamp has a much better chance than most of the models and predictions give her, the heavily Republican lean of the state means it would be an upset if she won there. Still, I'm not going to count her out.

A couple of other states

Wisconsin: Tommy Thompson seems to have some momentum in the polls right now, but I think Tammy Baldwin will ultimately end up winning this Senate seat. I think President Obama is very likely to win this state, and that he will probably carry Baldwin over the finish line, if she can't quite close the deal on her own.

Indiana: There has been very little polling of this state since Mourdock's rape/abortion comment fiasco, but I think the poll that shows Donnelly leading by double digits is probably accurate.

Nevada: There is definitely a lot of uncertainty in this prediction, as Democratic candidates in Nevada have a history of outperforming their polls. Still, if the best result a Democrat can get is a tie according to PPP, I think it is safe to say that a Berkley win would be a significant upset.

I'm not sure if I'll make another update before election day or not. I suppose if I see some late movement in the polls in a state I might do so, but otherwise I doubt I'll have much reason to try to refine this any further.

Very hard to come up with a scenario where Democrats could lose the Senate now. It looks like they shouldn't need to rely on Angus King to have a majority, even if some of the tossup states I have going Democratic end up breaking to the Republicans. I'm astounded that I actually have the Democrats making gains from 2006, considering how overwhelmingly Democratic that year was, but Republican self-destruction in Missouri and now Indiana has made this possible.

I expect I'll have Indiana in the Leans Democratic column once we get some new polling there, but for now I'll reserve judgement. It took a little while for the polls in Missouri to turn hard against Akin, and we might see the same thing in Indiana. The one reason it might be quicker is that Mourdock's comments came while everyone was paying attention to the race, while Akin's came while a lot of people weren't yet tuned in.

Starting to feel really optimistic about the Senate. Romney is starting to drag down the down-ballot candidates, and unless he can turn his campaign around rapidly, the map could break even more heavily Democratic than this.

Turns out Todd Akin is an even more terrible candidate, and human being, than I thought.

Just a few minor changes. I do think McKaskill is in fairly deep trouble in Missouri, but getting Akin as her opponent just barely keeps that state in the tossup category. I still think that Indiana will go to the Democrats, since Lugar lost the primary there.

I'm quite surprised that North Dakota and Montana look as viable for the Democrats as they do, considering the President isn't all that popular out there. It would be nice to hold onto one of them, but I'm not willing to call it that way just yet.

In Maine, I expect Angus King to caucus with the Democrats after winning the election, so the Dems will have a working majority of 52-48.

I probably won't be updating this much until the primary season is over, but here is my preliminary 2012 Senate map.

Note on Indiana: I have a feeling that Lugar is going to go down to defeat in the primary, hence the chance for a Democratic pickup there. If he wins the primary, then it goes back to solid Republican.

Arizona, Massachusetts, and Montana could all go Democratic if the Obama campaign works to drive up turnout there, but I'm not yet willing to assume that that will happen.