Now that the 2012 battle for the White House is officially underway, the New York Times' Nate Silver has compiled a handy guide of things for political junkies to look for as we are inundated with polling date. One item that merits our attention is President Obama's approval rating:

In the early stages of general election campaigns, a president’s approval ratings have often been at least as accurate a guide to his eventual performance as the head-to-head numbers. Thus, for at least the next couple of months, I would pay as much attention to Mr. Obama’s approval ratings as his head-to-head polls against Mr. Romney.

It is probably slightly better to look at Mr. Obama’s net approval rating — his approval less his disapproval — than the approval rating alone.