I forget who earned the hat tip, but I came across this graph from National Media Research, Planning and Placement about both the political preferences and activity levels of viewers of different major sports (click directly on the picture for a better view):
If this is to be believed, viewers for all major sports except the NBA skew Republican. The NBA is the only major sport I follow in the slightest, so I found this somewhat amusing. The PGA tour has both the highest voter turnout and is the most Republican (not surprise), while WWE fans are the second most liberal and with the lowest turnout (ah, another non-surprise). What did catch me off guard was the NHL's spot on the chart, which indicates a moderately conservative viewership. I would have guessed that the sport would be exponentially more popular in Blue States because of geography, and along with it would have a more liberal following. I welcome any insights into any part of this chart, as I'll readily confess to knowing much less about professional sports than the average TV watcher.
Update: I've came across a larger document from NMRPP that provides a similar chart regarding other TV viewing habits.