Today, President Obama’s Gallup approval ratings are at an all-time low (38 percent). For the last two weeks, his approval rating has basically been stuck around 40 percent. For the last 60 years, an incumbent president running for reelection has basically received in national vote share the same percentage as his Gallup rating going into Election Day. If a president’s approval was 50 percent or more, it didn’t matter who his opponent was, he won. And if a president’s approval was below 45 percent, it didn’t matter who his opponent was — he lost.
Matthew Dowd, The Atlantic, August 24