Rush Limbaugh's Close Victory

HRC wins IN (such as it is) thanks to Operation Chaos

Jon Chait from TNR did the math last night before it became apparent that her margin of victory would be 2%:

One exit poll question asks Indiana voters who they would support in a Clinton-McCain contest. 17% of them say McCain. Of those voters, 41% say they would vote for McCain over Clinton. In other words, these voters, 7% of the Indiana electorate, voted for Clinton in the primary but have no intention of supporting her in the fall.
Now, this isn't a precise measure of the "Limbaugh effect" -- no doubt there are some Republicans who backed Obama in the primary out of anti-Clinton sentiment, but plan to vote for McCain in November. But it is a good place to start when making a ballpark estimate. And it's a sizeable number -- 7% may wind up being as big as her margin of victory.