Eli Lehrer explains why approval rating "floors" matter much more than ceilings – and Obama’s lows are currently "higher than those for any President since Kennedy":
Right after 9/11, when President Bush gave some excellent, inspiring speeches and promised resolute response to terrorist attacks, many people who think very little of his policies voiced their approval for him in a time of crisis. He had a 92 percent approval rating at the time. Nonetheless, nearly half of the country voted against him three years later. The ceiling on a president’s approval rating, in short, doesn’t matter much since many of the people expressing “approval” won’t actually vote for the President. …
A president’s approval rating "floor" on the other hand, does seem to reflect something real: the number of people who will stick with the President's policies even in very tough times. … For Obama, a 41 percent "floor" this means that he only needs to attract roughly 10 percent of the population to support him over his opponent since at least 41 percent of voters (and probably more than that) will likely select his name no matter. This won’t be easy. But it is yet another reason that Obama faces pretty good odds of winning a second term in office.
Ponnuru is on the same page.