I suspect the drawn-out Democratic primary campaign will help John McCain and he'd better hope it does because things look terrible for him in this WaPost/ABC poll:
Illinois Sen. Barack Obama leads McCain, who captured the delegates needed to claim the Republican nomination Tuesday night, by 12 percentage points among all adults in the poll.; Sen. Hillary Rodham Clinton (N.Y.) enjoys a six-point lead over the presumptive GOP nominee. Both Democrats are buoyed by moderates and independents in the head-to-heads and benefit from sustained negative public assessments of President Bush and the war in Iraq.
Of course early polling is basically worthless but what you'd expect to see is, over time, early polling converging with the fundamentals. Like maybe big picture indicators make things look good for one party, but the other party nominates someone with a super-awesome reputation so he has the lead. Then comes campaigning, attacks, slime, and basically the fundamentals take over. But the fundamentals for McCain are terrible -- bad economy and an unpopular war.
For whatever it's worth, I think the considerable evidence (seen in this poll and elsewhere) that a larger number of people are open to voting for Barack Obama than are open to voting for Hillary Clinton is a better indicator of electability than is the fact that Clinton is more popular than Obama among Democratic loyalists in several large states, but I don't think either data point is worth very much.