How is the GOP doing in re-constituting itself specifically in the "fiscal cliff" negotiations?  Badly, according to these sources (h/t Taegan Goddard's Political Wire):

MSNBC's First Read:

In covering politics, you always want to resist the temptation to overstate things. After all, what's up one day can go down the next. But it's difficult to see what took place in Congress last night (failure to pass "Plan B") as anything other than an unmitigated disaster and embarrassing blunder for House Republicans -- all over something that was viewed as a negotiating tactic or PR move.

National Review Online's Rich Lowry:

If part of what President Obama was after was Republican humiliation and disarray, it's going better than even he could have hoped.