Democrat-held seats likely to be picked up by Republicans (4): West Virginia, South Dakota, Montana, Arkansas

You’ll find that our characterization of the 36 races in most cases is very close to that issued by such forecasters as the Cook Political Report and Rothenberg Political Report. We’re looking at the same sort of information they are, and they have strong track records, so it’s natural there should be similarities.

One point of difference is that we’re much more pessimistic about the Democrats’ chances in West Virginia, South Dakota and Montana. These races have a lot in common, taking place in three red states where longtime Democratic incumbents have retired.

We’re bullish on Republican chances in these states for simple reasons. First, they’re red states. Second, we think the national political environment modestly favors Republicans. Third, we think the Republicans are poised to nominate equal or superior candidates in each state. Fourth, our research suggests there is little or no carry-over effect from incumbency once the incumbent himself retires. In West Virginia, for instance, the retirement of Democrat Jay Rockefeller provides little information about how the race will turn out in November.