Equally as true, those who incite violence at "rallies" do self-identify as both "leftists" and "anti-Trump(R)" as they wanted Hillary(D) or Sanders(D) to win as well. 

1) The Anti-Donald Trump Protestors Who Attacked Democracy 
2) Donald Trump's Rally in Chicago Canceled After Violent Scuffles-Around 10,000 people had signed up on Facebook to take part in one anti-Trump march...
3) Protesters Take Anti-Trump Message to His Doorstep, and Plan Next Steps
4) Violence erupts at pro-Trump rally in Huntington Beach
5) Anti-Trump protests turn violent, 2 cops hospitalized...Protesters and law enforcement clashed on Inauguration Day