SurveyUSA have been polling to see how Obama and Clinton might do against McCain if the election was today. Their polls predict that either would win in the electoral college, but Obama's win is by a higher margin.
The chart below plots their relative state-by-state performance according to the poll.
Blue states both of them win, red states neither of them win, gray states one wins and the other loses. Obama does better in the states above and to the left of the diagonal, while Clinton does better in those down and to the right. The lines flanking the center lines show where the margin of preference exceeds 10%. DC was not surveyed and is not shown; no Democrat could lose DC. The area of the circle is proportional to the number of electoral votes that state has to give.
I'm amazed at the huge disparity in their performance in some states. Arkansas, West Virginia and Tennessee are all wins for Clinton, but Obama loses them all by over 15 points, while at the other end of the scale North Dakota is a win for Obama but a 19 point loss for Clinton, and Washington state is a loss for Clinton but a 14 point win for Obama.
Here's the same chart zoomed in:
Obviously the usual limitations of such polls apply; still, the scattergram makes vivid the different battles the two candidates would face in the run-up to November.
(Edited: charts improved)