I'm not sure I'd read too much into this story, where Chuck Schumer and Lindsey Graham are plugging a bipartisan outreach on immigration reform. Minor problem; Graham's low-hanging fruit, as one of the more moderate Republicans.
The Democrats have 55 seats counting Angus King, the new Maine senator-elect. That still leaves them 5 seats to get cloture, and King replaces Olympia Snowe, so there's only one RINO Sister left from Maine, Susan Collins. Also, Dick Lugar will be retiring, replaced by a Democrat thanks to Richard Mourdock's ill-timed foray into theodicy. Scott Brown also was replaced; thus, three likely targets in a race to 60 are already in Democratic hands.
If 2010 trimmed off a number of Blue Dogs, 2012 has trimmed off a few RINOs, leaving the parties a bit more polarized. In the drive to 60, you have McCain, Graham, Collins and...two more to go. Easier said than done. Kirk would be one strong prospect from the moderate camp, but it will be harder than in the past to patch together enough moderate Republicans to do a center-left 60-vote filibuster-buster.