LIEBERMAN'S DECLARATION OF INDEPENDENCE. Mike Tomasky explained it best last week. Just read the whole thing -- or if you read it already, read it again. Greg Sargent, for his part, writes this about a potential independent Lieberman candidacy:

if I understand this dynamic correctly, any success Lieberman has in portraying the Dem at the top of the ticket as too far to the left will likely complicate efforts by down-ticket Dems -- such as these House candidates -- to win over moderates, independents and centrists.

Which raises the question: Even if Lieberman is resoundly defeated in the primary and -- unlikely as this may now seem -- withdraws from the race, wouldn't the same line of attack be available to the Republican Senate candidate? In the most recent poll I've seen, Lamont wasn't running much further ahead of Republican Alan Schlesinger in a head-to-head matchup (17 points) than Lieberman was running ahead of him (15 points) in the primary. Those look like a solid leads in theory, and with plenty of room to grow, in Lamont's case, given that 34 percent were undecided between him and the Republican, but, as we are seeing with the Lamont-Lieberman contest, such leads are potentially susceptible to rapid evaporation in this rather volatile race. Meanwhile, Lieberman had a 36 percentage point lead over Schlesinger in a three-way matchup, thanks in no small part to his support from independents and some Republicans.

As Mike noted last week, the plurality of Connecticut's registered voters are undeclared in terms of party affiliation, and a candidate who can win support from Republicans and independents can win election in the state just as easily as one who wins support from Democrats and independents. I'd expect that a Republican attack on Lamont that tried to paint him as in thrall to a bunch of left-wing radicals would also do him some serious damage, especially if the national GOP got involved. Connecticut is not a terribly conservative state, but it's rather stodgy and somewhat wealthier than average, and culturally not much of a fan of anything too radical in tone. Lamont seems like a solid progressive candidate with a moderate demeanor, which should help him reach out to undecideds, should he face a Republican in the general. But no matter who his main opponent turns out to be -- Schlesinger or an independent Lieberman -- in a general election contest (that is, if he moves beyond the primary), he'll need to figure out a good counterattack against the unfounded charges of radicalism that are sure to be coming his way.

--Garance Franke-Ruta