When I write "Democratic" I'm not writing that the WNBA advocates an egalitarian political system characterized by equal participation and representation. Rather, I'm writing about the political party that WNBA fans belong to.
The accompanying graph - full size at this link - should be self-explanatory. The horizontal axis represents the political spectrum - the left side votes for the Democrats, and the right votes for the Republicans. The vertical axis represents how likely the fans of a certain sport are likely to vote - the upper part indicates high voter turnout and the lower quadrant represents low turnout.
The study, which was commissioned by National Media Inc. (a Republican firm) and whose polling was conducted by Scarborough USA, has implications primarily when it comes to deciding where one wishes to spend money on political advertising. The actual proportions shouldn't be surprising - as some commenters in the link noted, sports viewership is dominated by white males, and while males strongly tends toward supporting Republicans.
Which sport do you want to target if you're a Republican running for office? Probably college football - it's a large audience, it has decent turnout at the polls and it's predictably Republican. PGA Tour followers have a higher turnout and are more Republican, but there aren't as many of them. What if you're a Democrat? Probably the NBA, which has average voter turnout and whose fans tend to vote for Democrats. The WNBA's fans are most likely to vote for Democrats, but they aren't numerous enough to spend a lot of cash on. (Although if it's a close election, and you need to pick up a few thousand votes....)
I don't know if this study does anything than confirm our own biases, but the graph is definitely interesting to look at. If you're a WNBA fan looking for ideological fellow-travelers and are looking to change sports, call David Stern in New York - I think he has a sport to suggest.