This question doesn't really make any sense. In the traditional sense, if the candidate at the top of the ticket has "coattails", it means that candidates down-ballot benefit by the presence of that up-ballot candidate.

The problem with this question's construction is that Rep. Fattah has no real opposition, and Sen. Casey is, of course, not up for re-election for another four years.

It is literally impossible for Obama's coattails to help Bob Casey in this election. You could certainly speculate as to whether Casey's endorsement of Sen. Obama will keep him from having a primary challenge in 2012 if a President Obama is again at the top of the ticket, but isn't that jumping the gun a bit here?

As far as Fattah's future is concerned, I'm not sure if the person who formulated the poll would think that Fattah's support of Obama would help him to nail down the Democratic Mayoral nomination in 2015, but again, that has nothing to do with possible coattails in this election.

The better question is whether an Obama "coattail" effect exists for people who are (1) actually on the ballot, (2) with real competition, (3) this year. Perhaps the Obama campaign will drive up turnout in the black community in Erie and will mean more votes for Kathy Dahlkemper ... but in my view that's really the only plausible scenario where an Obama presence at the top of the ticket might make a marked difference in a down-ticket race.