There's mostly white people at right-leaning events because the right is more white than black. That is just a simple fact that really need not be construed as being of or related to racism.
The right is just about completely white.
Fewer Voters Identify as Republicans - Pew Research Center
The balance of party identification among African American voters has remained relatively stable in recent years; the Democrats now hold a 72% to 4% advantage, virtually unchanged from 2004. White voters now are as likely to identify with the Democratic Party as with the GOP (31%). This represents a significant shift from four years ago, when white voters called themselves Republicans by a 38% to 29% margin.
Again, I'm not calling these events racist. However, if you have people advocating violence saying we need to kill that _________ then how do you think it's going to look? If a bunch of African Americans were marching down the street saying we need to kill that cracker, how is that going to look?
It doesn't matter what the political leanings are because it all comes down to race. Even to this day, across the country, there is so much tension that is eventually going to boil over. Why is this? Cause people on both sides of the political spectrum make it seem like it's wrong to talk about our differences and that it's wrong to talk about the past. However, if we don't confront the past, and get past it then we'll always be stuck there instead of moving on to the future.
Sure, openly in most areas it's alot better then 40 years ago. However, has it gotten that much better personally for people? Partly yes, partly no. Alot of people don't even think of themselves as racist because they hold these myths such as Blacks are thieves, Hispanics are lazy, Arabs are going to kill us all, or whites are just trying to keep everyone down as true.
One of the best ways to do this in politics is to have people in the Republican Party encourage a more diverse party. If people don't feel like they're welcome into the party, they're not going to want to join. Oh, by the way, I do feel Michael Steele is going the wrong way about that, and in many ways just playing into stereotypes of sorts on who he can recruit to join. However, if both parties were diverse, and open to frank/honest discussion then alot more can be done.