(Update below.)

Over at 538.com, Tom Shaller has posted an overview of the most vulnerable Democratic House seats in 2010. The site doesn’t do on-the-ground political analysis so much as crunch numbers and assess macro factors like fund-raising.

In this case, Shaller took numbers on the races from the Cook Political Report and then added a few factors. In all, they included: The rep’s votes on health care and cap and trade; the traditional political nature of their districts; their most recent win margin; and the cash on hand they and their potential opponents have.

The bad news for Arizona Democrats is that two local House seats by these measures look vulnerable. Indeed, Harry Mitchell, of the Arizona fifth, is one of the nine most vulnerable across the country.

Gabrielle Giffords, from the eighth, is one of fifteen members on the next-most-vulnerable tier.

Their districts are superficially similar, with urban anchors in the affluent eastern parts of Phoenix and Tucson, respectively.

The Cook report is a very sophisticated operation (as 538.com is as well); I’d just make one observation that neither seems to have noted in the case of these two races; that the Arizona Republican vote in 2008 was skewed because of McCain’s favorite-son status.

McCain got less than 52 percent of the vote in Mitchell’s district, and just above 52 percent in Giffords’. It seems arguable that both would have gone at least slightly Democratic were anyone else running on the GOP side.

That said, the 2010 campaigns will be run in a much different political climate, and one without the energized folks who came out for Obama. Both parties are prepared for significant Democratic losses next year, and it’s possible two of them will come from Arizona.

For a GOP perspective on the race in the eighth, Greg Petterson points to the recent deposing of a longtime Democratic city council person in Tucson and offers this assessment:

When you are trying assess how Tuesday’s election will affect the 2010 race, remember that Tucson is the Democratic core of Gabby Gifford’s district. Yet, if the election were held today, Giffords would have to struggle to win an election in Tucson itself. Add back the Republican portions of the district and CD 8 is looking like solid Republican territory.

p.s. : As I noted above, the 538.com analysis wasn’t on-the-ground political prognosticating. It was all about crunching the numbers. Here’s the EVT’s Le Templar, who is on the ground, on an Arizona House race that didn’t get the blog’s attention:

The vice president is raising money today for one incumbent not included on that most-vulnerable list: Ann Kirkpatrick. The Congressional District 1 race is flying under the radar because Democrats have more registered voters and Kirkpatrick’s potential challengers haven’t raised much money, yet. But the district is quite conservative and Kirkpatrick won her first term in the fallout from former Rep. Rick Renzi’s criminal indictment for political corruption. There’s also this video where Kirkpatrick literally walked out of a meeting with her constituents. Expect that video to get a lot of air time and blogger references in the coming year.

My guess is Kirkpatrick will be at least as vulnerable as Mitchell and Giffords next year.

Arizona’s polity is obviously in a state of upheaval from top to bottom, and as it moved from red-state to swing-state status there will certainly be volatility. But speaking generally about the Democrats from the national perspective, it strikes me that what too often isn’t noticed is that bad times for the Democrats and the new president came conveniently early.

Just a year from the election the country seems to have hit bottom. The health-care debate and unemployment are still drags, of course. (And might turn out to be game-changers on their own if they are not resolved by next summer.)

Still, it’s an odd advantage, but an advantage nonetheless, that the party has a year to deal with the problems rather than a period of months or even weeks. That they might be resolved during that time is a possibility that is too-infrequently raised, I think.