Yeah, it don't make any sense to blame on us for those problem and I don't condone the violence against the political parties, also we are no anarchist, however anarchists tend to challenge with police officers and haters over politicians.
The election is best answer for problem with political parties, not violence. It will take more time for political parties to make change.
Of course, Obama wanted all of us to be united, however some people don't want to be united due to feuded with racism, also Obama criticized the law enforcement agencies that contributed to tension with law enforcement agencies, also some law enforcement officers believe in corruption or dirty job over reform.
Some white supremacists got involved in law enforcement agencies after loss of segregation and passage of CRA so they could throw the revenge on minorities and unlikely to found guilty in the court.
Yes, it is awful and he is in critical condition, that's not good signal right now. It will going be long recovery for him like happened to Gabby Giffords.