Democratic Senate Gains in 2010

[Kaine for Senate '18]

For 2010, things look pretty interesting.  The GOP has, by my count, and barring anymore retirements, 11 seats that are safe GOP (AK, AZ, UT, ID, KS, OK, IA, LA, AL, GA, SC).  They then need to defend 8 more seats.  They're going to be in the same position they were in in 2008; they need to spread their money around to defend more vulnerable seats, and therefore unable to really attack the Democrats.  In pretty much every single one of these states, there is a Democratic bench that can run strong candidates.

By contrast, the Democrats have 12 seats that are safe Democratic (HI, CA, OR, WA, ND, WI, IL, IN, MD, NY1, NY2, VT), and another (CT) which will likely be safe by election day.  This means that they will likely need to defend at most 3 seats, 2 of which have established incumbents and a weak GOP bench.  CO is the only state that isn't safe/having an entrenched incumbent, and the GOP bench there is almost empty.

The Democrats, then, will be able to spend a much higher amount attacking Republicans than vice versa.  This will be the last year that the Democrats have this advantage, and they need to take full advantage.

[Kaine for Senate '18]

Well, there's Owens who probably won't run and Generic Pseudolibertarian Businessman #5

That bad?  Yikes; I'd say the state is probably safe then.

[Kaine for Senate '18]

I thought the president's party usually loses out in Midterm elections.

It varies a lot more for Senate elections than House elections. Look at '02 and '98. The individual seats at stake matter much more, and in 2010, that favors the Democrats because the Republicans had done so well in 2004.

Yeah, exactly.  This is the final cycle where the GOP is going to be spread so thin; starting in 2012, the roles are reversed again.