I mentioned a week ago that Sen. Chris Dodd (D-Conn.) was seriously weakened politically heading into 2010. Confirmation continues to come in. The Cook Political Report, which ranks every Senate race, updated its ranking on Friday and moved Dodd's seat two categories in the direction of more imperiled (that's a big move in these matters) from "likely Dem" to "toss-up."

Chris Cillizza, who blogs politics for the Wash Post, publishes a top 10 list of the seats most likely to change parties. On Cillizza's latest list, published Friday, Dodd's seat, which wasn't mentioned in the top 10 of the previous edition, appears as the fourth most endangered (also, a very big move for those who watch these kinds of rankings).

But the overall picture remains very bleak for the Senate GOP caucus. In fact, of the top eight seats that Cillizza rates most likely to change parties, seven are currently held by Repubs (Dodd's seat being the only exception). As you know, assuming that Al Franken will be seated before 2010, the Dems would need just one net pickup to reach the nominally filibuster-proof majority of 60.

Cook's new rankings are a little happier for Repubs, but not much. Charlie has seven seats in the toss-up category, five now held by Repubs. (If you're curious, the other Dem seat that Cook rates a toss-up is the Illinois seat held by the recently-appointed Roland Burris. But I assume that vulnerability declines considerably if, as seems likely, the Dems nominate anyone other than the Blago-tainted Burris.

And, if you didn't click through to see Cillizza's list (and his explanations) for yourself, his most vulnerable list goes thus:

1. New Hampshire seat, from which Repub Sen. Judd Gregg has announced his retirement.
2. Kentucky seat, from which incumbent Repub fireballer Jim Bunning has rejected Repub hints that he take a powder.
3. Missouri seat, from which long-time incumbent Christopher (Kit) Bond has announced his retirement.
4. Connecticut: Dodd.
5. Pennsylvania seat, held by long-time incumbent Arlen Specter, whom Cillizza believes will face a tough primary challenge.
6. Ohio: Repub incumb George Voinovich is retiring.
7. Florida: From which Repub incumb Mel Martinez is retiring.
8. Louisiana Repub incumb David Vitter is seeking a second term.
9. Colorado: Newly-appointed Dem Sen. Michael Bennet will face voters for the first time.
10. Illinois: The Burris seat, which Cillizza thinks is less likely to end up in GOP hands than Cook thinks.

I'm sure I obsess a bit much on the 2010 Senate lineup, with miles to go before the electorate weighs in. But I do think this: Repub efforts to restrain the Obama and Dem Congress from fully implementing their program will be a theme this year and next and will create some smoke about who gets credit/blame for whatever good/bad happens. If the Dems hold the White House, a big House majority and a filibuster-proof Senate majority heading into 2012, it will set up a huge referendum on how the country feels about letting one party run the government, whether the big Dem gains of 2008 were a sustainable realignment, and how long the country is going to hold Bush against the GOP.