How Many Senate Seats Will Democrats Lose in November?

William Galston wrote in the New Republic today that Democrats are at risk of losing the Senate in the midterm elections. Below, CBS News chief political consultant Marc Ambinder offers an insider's breakdown the current landscape.

The bottom line on the Senate, from my perspective, is that Democrats could lose 3 seats -- or they could lose ten, and their majority.

There are absolutely ten seats in play...from Patty Murray of Washington's on one edge to Vice President Biden's old seat in Delaware on the other.

There'll be plenty of outside money from labor and other sources, but Democrats don't have the money they need to play defense in ten places.

Galston's piece is newsworthy only to the extent that Democrats get riled up about it. They are, in a sense, creating their own bad luck. Expectations absolutely matter in off-year elections where voters will simply not show up at the polls if they consider their votes to be worth it.

The frustration you feel is palpable: Democrats can pass historic health care legislation; a major Wall Street reform package; President Obama can act like a strong commander in chief by firing his general; and the numbers get worse. Damned if they do, damned if they don't.

On to the specific races:

• Democrats are safer in Colorado than Galston seems to think. The GOP internals I've seen show Democrat Michael Bennet leading by six or seven points.
• Democrat Barbara Boxer has been in this place before, although Republican challenger Carly Fiorina's cash and GOP gubernatorial candidate Meg Whitman's buy-a-voter program could really make a difference this time.
• Right now, neither party is terribly energized in Wisconsin and Washington - the primaries might determine how energized Republicans truly are.
• Independent Charlie Crist has a five point lead in Florida in the last reputable poll I saw.
• Senate Majority Leader Harry Reid is doing better in Nevada...in some polls he is tied, in others he trails slightly. He used to trail a generic Republican by double digits.
• Democrats seem much less worried about Illinois, and Mark Kirk's military braggadocio scandal really hurt him.
• Remember how vulnerable Dick Blumenthal was thought to be in Connecticut after HIS gaffe? Now he's OK.
• Kentucky - Republicans should be leading. They're not. (The demographic profile of the electorate will tip the race to Rand Paul at the end of the day if he keeps it competitive.)
• Missouri - Robin Carnahan is running a very very good race for a Democrat, and this will be a lot closer than people think.
• Republicans are going to retain the New Hampshire seat, pick up the Delaware seat, and pick up North Dakota.
• I suspect the environment alone will push some of the other seats their way. But they're not there yet.

After Labor Day...we'll know a lot more.

Interactive Map: CBS News Election 2010 Race Ratings