Hey, Who Left the Party?

This analysis was written by Anthony Salvanto, CBS News' manager of surveys:

In the latest CBS News/ New York Times poll 32 percent of voters who call themselves Independents or Democrats today say they used to be Republicans.

That may not be surprising given the President's low approval ratings, but here's what it could mean for 2008:

Sixty-three percent of them now think of themselves as Independents. Fewer, 37 percent, have become Democrats. These erstwhile Republicans are backing Obama today by 43 percent to 30 percent.

Looking closer, the former Republicans divide into three segments: those probably gone for good, those probably going back, and those still up for grabs.

Thirty-one percent of former Republicans say they're voting for Obama and that their mind is made up about it.

Sixteen percent indicate they'll come back to the fold, at least at the ballot box: they're voting for McCain and their mind is made up, even if they don't label themselves partisans anymore.

The remaining half, though, look like swing voters, and a very important bunch of them for the GOP, having voted for Bush by a 2 to 1 margin in 2004.

As whole, the demographics of former Republicans are mostly men (55 percent) and mostly white. This is important because in recent years, successful Republican presidential campaigns have relied on very heavy support from white men – above and beyond the white women's vote - to rack up winning margins.

These former Republicans are paying as much attention to the 2008 race as other voters, and the economy is their top issue, too. Like most Americans, they overwhelmingly say the nation is on the wrong track.

Today, in part because of these ex-Republicans, the Democrats lead among registered voters 39 percent to 28 percent. These poll findings are also in line with the trends now coming out of some key states that formal registration has shifted toward the Democrats, too, as we reported earlier this week.

One important caveat: partisan identification is a state of mind, and so it can - and often does - shift around for many people. Sometimes voters pick the candidate first, and then express a party identification to match, not the other way around. One need not go far back to see fluidity in partisanship, or turnout: exactly four years ago, in July of 2004, the Democrats had an edge of 38 percent to 31 percent among registered voters in a CBS News/NY Times Poll. In September, the Republicans had a lead. On Election Day the partisan breakdown among actual voters was even.