Large-scale demonstrations don't necessarily draw the most refined participants, but they provide a useful cross-section of the relevant interest group. Right now, dueling rallies are being held in Wisconsin between left-wing union Democrats and right-wing Tea Party Republicans.
Power Line has a good blog post on the Tea Party's pro-democracy anti-demonstration, with pictures of clever rally signs and videos of political speeches. Like all Tea Party rallies, the demonstrators will likely leave the area in a cleaner condition than they found it and the media will search in vain for any sentiment of racism or untoward vulgarity.
The Power Line post also provides unique coverage of the anti-democratic union rally, with videos of doctors illegally writing fraudulent sick notes for union protestors. Michelle Malkin reveals the sort of toxic and violent rhetoric common to protest signs at liberal rallies.
From calls for African American lynchings at Common Cause rallies to a shut-down of the Wisconsin legislature due to threats of violence, liberal protests always seem to contain the most degenerate sort of behavior. Pro-life advocates hold prayer vigils while pro-choice advocates countenance child-rape and sex trafficking. Republicans in the minority complain on Fox News Sunday morning talk shows, while Democrats in the minority abandon their posts and shut down the government in order to subvert the democratic process.
This isn't a scientific analysis of character composition among political ideologies - but it's a solid starting point.