On the one hand, having Warner out of the running allows for a consolidation of the right-of-Hillary forces in the party behind one of the remaining right-of-Hillary candidates – the strongest of whom looks to be Evan Bayh (sorry, Joe). If he isn’t gunning to be on Clinton’s ticket, Warner can take harsher shots at her now that he’s not a candidate himself, and he’s developed something of a base to throw behind Bayh.
On the other hand, Warner was probably the stronger of the right-of-Hillary contenders. Unlike most of the Democrats in contention, his experience is executive rather than legislative, which both builds credibility with a certain crowd and makes it easier to straddle certain ideological razors that Senator Bayh is more likely to slip on. And his business experience helps pry certain networks and wallets open that a right-of-Hillary candidate in particular will depend on. Warner in particular was probably best situated to compete in terms of star power and red state outside the beltway cred with John Edwards, who is gathering more and more of the left-of-Hillary energy behind himself.
So Warner’s exit seems likely to leave the right-of-Hillary crowd more unified but behind a weaker contender. Which in the end I suspect is good news for the left-of-Hillary crowd. And therefore bad news for her. Which in turn is bad news for the other side of the aisle.