Staged protests like the one that saw Donald Trump rally goers pelted with eggs and rocks in San Jose, California, originate from progressive political strategy to get Hillary Clinton elected.
The campaign trail protest is a bullseye tactic for the progressives to draw public attention. Political progressive masterminds know for a fact that the mainstream news media will post pictures of the innocents bloodied by the rent-a-mobs, and hopefully frighten people off from attending Donald Trump rallies.
But the main intent of the staged protest of the day is to seize the opportunity to portray Trump supporters as redneck racists, bigots, homophobes--who refuse to share their children's school bathrooms with transgenders--and Islamophobes.