Rasmussen has an interesting poll out on Pennsylvania Senator Arlen Specter and the stimulus package. They report that by a 40-31 margin, Pennsylvanians are less likely to support Specter because of his support for the stimulus package rather than more so. This is in spite of the fact that a slight plurality of Pennsylvanians favor the recovery package -- 47 percent in favor against 41 percent opposed. This outcome emerges because Republicans, and to a lesser extent independent voters, are more willing to blame Specter for his vote on the stimulus than Democrats are willing to give him credit for it.
The thing about a situation like this, however, is that not all votes may be created equal. In particular, losing support among Republicans may be damaging to Specter -- in the Republican Primary, where he might or might not receive a serious challenge. But provided that he survives the primary, are Republicans -- and the Republicans that remain in Pennsylvania are a pretty hardened lot -- really going to vote against him in the general election?
Meanwhile, Specter is relatively dependent upon the votes of at least some Democrats. In 2004, when Specter was re-elected, about 26 percent of his support came from Democrats, and the Democratic advantage in registration has increased significantly since then.
The "tiebreaker" may be that independent voters also appear more likely to blame than to credit Specter for his vote on the stimulus. On the other hand, there aren't all that many independents in Pennsylvania, and Rasmussen has consistently shown less support for the stimulus than other firms, so there may be something of a "house effect" in play.
I don't think it's clear, in other words, whether voting for the stimulus was a net positive or a net negative for Specter in terms of his re-election chances in 2010. It is clear, however, that it must have been a tough decision for him.