I think it'll wane. Had the momentum of candidates that won the first debate held steady, then Kerry would have beat Bush and Mondale would have beat Reagan. Maddow did about 15 minutes on this subject last week - basically, for ALL televised debates, every non-incumbent has been judged to have won the first one with the exception of 1996. Furthermore, what is the track record among those who won the first debate? 3 won election, 3 were defeated.
I think it will essentially make the race a coin-toss for the amount of time that it holds, which should help Romney's 538 numbers at the very least.
That's a silly and naive argument because Bush Jr, and Reagan were on stronger economic ground than Obama. In addition, Mondale and Kerry were seen as weak left-wing liberals. Mondale was part of the failed Carter presidency so Americans didn't trust him at all. Kerry could never shake his left-wing anti-Vietnam, massachusetts liberal image.
Romney is far more viable opponent with stronger constituencies than the various liberal factions. The Republican base is far more reliable at voting and focused than the liberal base.
