that had there been no deal, the Repubs would have invoked the nuclear option with big fat disgusting Dick Cheney being the 51st vote.  So, ineffect, the deal merely served to put off the nuclear option.  Now, even if a few of the Repubs decide the deal is off, perhaps. . . just perhaps, there will be a few others to take their place -- especially if the nominee is really shown to be a rigid ideological extremist.  It's one thing to stand with your party's President on this matter when he has a 51-52% approval rating; it's a little bit harder to do so when he has a 42-43% approval rating.  Further, I think that invoking the nuclear option over an ideological extremist Supreme Court nominee may have far more negative political implications than doing so over lower court nominees.

In sum, I think it may be a tad premature to worry that "the deal" will bite us in the back.