A simple Google search would reveal a ton of examples of Trump supporters beating, pepper-spraying, intimidating, and being belligerent towards Trump protesters. I found 4 articles on the first page of results that talk about it, and are not from Huffington, etc.

And honestly, if you're going down the road of suspecting the alternate party inciting violence to destabilize a peaceful protest, you're probably on to something, but the facts are far cloudier, and definitely seems to happen on both sides, due to incentives.

For instance, it would have made logical sense for members of the right to incentivize Antifas violence at the UC Berkeley protests. But this is the sort of stuff that seems to come out way later down the road.