2006: The Terrain

There’s been a lot of talk, more than usual this early in the election cycle, about the 2006 Senate races and the odds of either party picking up seats and changing the dynamics in a Senate now perennially deadlocked over judicial nominations and other business. In fact, much partisan strategy over these battles will, as always, be shaped by the prospects for the next election – where the parties hope to gain, where they fear to lose, and whether they expect to be dealing from a stronger or weaker hand come January 2007. With that in mind, let’s take a look, using some hard numbers, at the political terrain for the 2006 Senate races.
There are polls, of course, but polls this early are volatile. Before we get to the polling data, there are two main pieces of hard data – actual votes – that we can use to evaluate the political climate in a state entering the beginning of a Senate race. The first is the red/blue issue: when people were paying greatest attention, which party did they side with? The polarizing nature of the 2004 election, with a conservative Republican and a liberal Democrat, sharpened that distinction. The second is the history of this Senate seat: how did the incumbent do in his/her last election? This second item is of particular importance where the incumbent is running again, although you do have to bear in mind that you are dealing with election results from six years ago, before 9/11, the Iraq War, the Florida Recount, Enron, judicial filibusters, Terri Schiavo, blogs, etc., etc., etc. Rather than rest on one or two of these data points, let’s combine the two. I present a ranking of the Senate seats to be contested in 2006, from most to least likely to change parties, based on adding (1) the incumbent party’s percentage of the vote in the last race for this seat (S%) to (2) the incumbent party’s percentage of the vote in the 2004 presidential election (P%) (all numbers from FEC sources here, here and here):

Observant readers will note that I’m missing a state, Vermont. The problem is that Jim Jeffords ran there as a Republican in 2000, so it’s hard to make anything of his 65.56%-25.42% thumping of his Democratic opponent. Kerry won 58.94% of the vote in Vermont, so if you double that and throw out the Jeffords anomaly, the D% should probably be 117.88, ranking the state near Maryland as an open seat the Democrats ought to be able to defend.
Notes:
A=Unseated incumbent in 2000 (or 2002, in Jim Talent’s case)
B=Won open seat in 2000
C=Ran unopposed in 2000
D=Ran against divided opposition in 2000
E=Won special election in 2002
These notes are important. John Kyl is in a very strong position, but he ran unopposed in 2000; he’s not quite as bulletproof as he looks. The Democrats may seem weak in several spots because they ran the table in close Senate races in 2000, but several of those candidates knocked off incumbents last time around, and will start in a stronger position this time around with the headwind of incumbency at their backs rather than in their faces. I figured “divided opposition” where the two main candidates pulled below 96%, leaving a number of voters on the table, but since Ted Kennedy beat his opponent 72.69%-12.86% in 2000, that doesn’t amount to much.
I’d hesitate to say what threshhold indicates a realistic chance of a seat changing hands, but obviously anyone below 100 has to be viewed as an opportunity for the other side, and anyone above about 110 is – other than open seats – an extremely tough race. You can see that most of the most competitive races, based on this criteria, involve Democratic-held seats.
Of course, all of this is prologue; the 2006 races will be fought, like every election, with a new backdrop of issues and partisan mood and momentum, which so far seems to be favoring the Democrats. The number of genuinely competitive races is bound to be reduced if credible challengers can’t be located, as was the case in 2004 in Nevada, for example, where Harry Reid was vulnerable but the GOP couldn’t get a serious challenger. But the numbers above at least provide a solid guide to where the needle stands entering those races, and how far it has to move to save or defeat the incumbents listed above.
UPDATE: Don’t miss Gerry Daly’s effort to tweak some of the variables here to create a more accurate measure. I don’t necessarily agree that the other Senate seat is all that instructive, as demonstrated by longstanding in-state splits: D’Amato and Moynihan, Grassley and Harkin, Domenici and Bingaman, etc. and the fact that some states just get in the habit of re-upping incumbents. For example, the persistence of Robert Byrd does nothing to help Jay Rockefeller. On the other hand, for similar reasons, I’m inclined to agree with a commenter at RedState that the last Senate election isn’t that useful in evaluating open seats, at least not in the case of someone like Frist or Sarbanes who ran as an incumbent six years ago.

UPDATE #2: Here’s the table re-done to just double the presidential vote in the four states where there’s an open seat: