I have been assuming that Indiana's demographics are similar to those of Ohio and Pennsylvania. But I have noted that Barack Obama has been doing better in polls there than he was in those two states, and I have read that Indiana has a younger population. So I decided to compare the 2000 Census Bureau demographics for Indiana with those for Ohio and Pennsylvania. It turns out I was wrong. Here's a table showing, rounded off to the nearest percentage, my calculation of the percentage of 18-and-over residents in the 55 and over, 35–54, and 18–34 age groups in each of these states.
These aren't huge differences. But in a contest where there have been bigger differences between the preferences of old and young voters, they're significant, and Indiana seems to be demographically more favorable to Barack Obama than either Ohio or Pennsylvania.