THE PROSPECT OF 60…. Periodically over the last few months, the notion that Democrats could go +9 for the cycle and claim a 60-seat majority in the Senate has popped up. The exuberance seems to die down soon after, when the political world realizes how exceedingly difficult this would be, even under the most favorable of circumstances.

The subject reemerged this morning, when Sen. Chuck Schumer, (D-N.Y.), chairman of the DSCC, told reporters he still thinks the filibuster-proof threshold may be within reach.

…Schumer and the Democrats have added other previous-cycle crimson states to their target list: Georgia, North Carolina, Mississippi and Republican Minority Leader Mitch McConnell’s seat in Kentucky. He went so far as to call Georgia and Kentucky “even-steven races.” The DSCC put up their first ad in Kentucky today.

Adding to those states, he sees Alaska, Colorado, Minnesota, New Hampshire, New Mexico, Oregon and Virginia as likely pick ups.

He said that Democrats are also closing in on Sen. Susan Collins of Maine.

Winning in Alaska, Colorado, Minnesota, New Hampshire, New Mexico, Oregon, and Virginia — the Dems’ best pick-up opportunities — would put the party +7 for the cycle. (Of those seven, I think only two — Virginia and New Mexico — are going to be easy wins for Democrats.) To go +9, Dems would have to win all of them, plus two of the other four competitive races: Georgia, North Carolina, Mississippi, and Kentucky. All of that assumes that Mary Landrieu, this year’s only vulnerable Senate Democratic incumbent, can hang on and win in Louisiana, which isn’t a sure thing.

And here’s one more twist: a net gain of nine would produce a 60-seat Democratic caucus, when added to the existing 51-seat caucus. That 51 includes Joe Lieberman, whose outrageous conduct of late has made some kind of party punishment seemingly inevitable after the election.

I’m skeptical about the Dems’ chances of getting to 60, at least this year, but if they do gain nine seats in November, what will the party do with Lieberman?

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.