Here’s one way to analyze whether President Obama has a “base problem” among Democrats.

Check out Gallup approval ratings database.

Jimmy Carter was under 50 percent approval among Democrats from May until January of 1980. At this point in the summer of 1979 he was at 37 percent among Democrats.  Sen. Teddy Kennedy announced his primary challenge of Carter in November of 1979.

Democrats ultimately “came home” to Carter, re-nominating him. But the primary with Kennedy was bruising and lasted all the way until the August 1980 Democratic National Convention. By September of 1980, heading into his contest with Ronald Reagan,  Carter’s approval rating with members of his own party was only 61%.

Obama’s approval rating among Democrats is now a much more robust 78%. And that is the same percentage of support among Democrats that President Bill Clinton had at this point in 1995.