A reader shared the link to an excellent table that was posted on the website FiveThirtyEight.com back in April:

Hillary performs fully 11 points better against McCain than Obama does among voters with a high school education or less. But Obama performs 6 points better than Hillary among adults with some college, 10 points better among college graduates, and 13 points better among those with postgraduate educations.

Rather than analyzing these numbers by themselves, let’s compare them to previous election cycles, and see how other Democratic nominees performed in these categories. I was able to track down exit poll data for 1992-2004, as well as 1976 and 1980.

Though it’s way too early for the 2008 numbers to be strictly comparable to the exit polls from previous elections, the table illustrates the differences in the support Obama and Clinton get against McCain and changes in the Democratic coalition over time. In particular, note how Obama does about the same as Kerry among high school-educated voters and those with a postgraduate education, but makes significant gains among those with some college or a college degree. By contrast, while Clinton gets more support than Obama from high school-educated voters, she doesn’t improve on Kerry’s showing with voters who have some college or college degrees and does 14 points worse among voters with postgraduate education.

Update 5/13 9:55 AM: A reminder — as BG points out in comments, these numbers collapse across other demographic categories such as age, race, and gender.