President Obama will struggle to win reelection if his approval rating doesn’t rise

The National Journal reports:

With the 2012 presidential general election just a year away, it’s a good time to look at the national polling and talk about the state of play. Obviously, we have to make allowances for changing circumstances and unexpected events.

The best barometer of how a president is going to fare is his approval rating, which starts taking on predictive value about a year out. As each month goes by, the rating becomes a better indicator of the eventual results. Presidents with approval numbers above 48 to 50 percent in the Gallup Poll win reelection. Those with approval ratings below that level usually lose. If voters don’t approve of the job you are doing after four years in office, they usually don’t vote for you. Of course, a candidate can win the popular vote and still lose the Electoral College. It happened to Samuel Tilden in 1876, Grover Cleveland in 1888, and Al Gore in 2000. But the popular votes and the Electoral College numbers usually come down on the same side.