Incumbent bounces don't fade: Romney is in more trouble than you think (a history)

It is a good morning. Gallup shows Obama with a growing lead, and Rasmussen this morning shows Obama up 4.   Better still, Politico reports Romney's own polling in Ohio has Obama up in the high single digits.

Ahh, but the press says, bounces fade.

Except for incumbents, history says they don't very much.  Post convention polling for incumbents is almost identical to the polling going into the first debate.  Here are the numbers:

The evidence is really clear: the race doesn't change much between the incumbents convention and the first debate.  Moreover, NO INCUMBENT WHO LED ON SEPTEMBER 15th HAS EVER LOST.

Some notes.
In 1980 the first debate was between Andersen and Reagan.  The second debate did not happen until much later.  In 1992 the numbers in late September are very contradictory - in part because speculation about Perot's re-entry changed the race.

In both 2000 and 2004 debates re-made the race.  Gore's lead of about 3 turned into a Bush lead of about 1.2 after the first debate, a lead Bush held to the last weekend.  In 2004 Kerry cut a 6 point lead to 2 - a margin that was mostly stable for the rest of the race.

Debates matter.  But the simple truth is that Romney is in very, very big trouble.