Right now, the Real Clear Politics average shows 50.6 percent of Americans with a favorable view of Mr. Obama, versus 45.1 percent with an unfavorable one. That contrasts with his approval ratings, which now show 46.8 percent as approving his job performance and 48.7 percent as disapproving it.

In other words, there is a small slice of the electorate, about 4 percent, that has a favorable view of Mr. Obama, but does not approve of his job performance. Given how close the election is, the way they behave in November could be decisive. If the election is a referendum on Mr. Obama based on his approval ratings, it’s going to be very close. He may be a slight underdog, especially since some of the approval ratings polls are of adults or registered voters, which are generally a point or two more favorable to the Democratic candidate than those of likely voters. However, if it’s a referendum based on Mr. Obama’s favorability ratings, his net-positive score (plus 5.5) makes him look like the favorite.