Most polls conducted immediately after a convention are nonsense. The jumps that some candidates have after their party’s gathering is called a bounce for a reason–bounces have two halves up…and down. Usually there is something that breaks the euphoria causing the electorate to focus on the candidates. In 2008 McCain lead from the end of the RNC to the end of Sept when he bungled his response to the economic crisis.
The Rasmussen polls released today reported the end of Obama’s post convention bounce and it may have been done in by Romney’s response to the the violent attacks of our embassies which began on 9/11.
Beginning with the Convention (which started 9/4) Obama’s three day average started to rise in the polls hitting a peak in the 9/6 to 9/9 three day average period. As the President’s share of voters went up the Romney numbers started to decline from the prime-time convention attacks (I meant the speakers not the mainstream media but they helped also). Romney’s % of the vote was stuck at 45% for a few days.