"The lesson seems to be that the voters’ verdict on the president after four years is very similar to their verdict on the president’s party after two years—except when the president changes course on policy (as Clinton arguably did) or except when circumstances change substantially (as they didn’t in my view in any of these cases). Of course I’m generalizing from a very limited sample of four election cycles.
The implications for Barack Obama are obviously negative, unless you think he is changing or will be perceived to have changed course on policy, or unless you believe circumstances will change substantially. So far the macroeconomic circumstances seem less helpful to him than they were in November 2010."
Statistical Analysis: 2010 election results mean bad news for Obama in 2012
Michael Barone | Washington Examiner: