That would be what one would expect the police to do. But in the Democrat run cities where Antifa and BLM riot at will the police do not defend the conservatives. In fact they usually arrest the conservatives who try to defend themselves after the police let the leftists attack the conservatives.
In every case, even obvious self defense the police and the DAs go after the conservatives. And they certainly don't keep the Antifa thugs away from the conservatives.
I think that conservatives planning a protest should FIRST go before the Mayor or city attorney and DEMAND safety precautions such as a safe distance between the two groups. That is a reasonable request. And, oh yes have an attorney of your own. The mayors are afraid of lawsuits. Another thing, have lots of easy to read signs so that your message comes across. What is the point of just standing there hollering at each other when nobody can understand what you are saying. Signs are the way to go. Pictures will be taken and sent all over the internet so that your views are seen by the public.
Look what happened to Nicholas Sandmann. His rights were attacked but he got himself a good lawyer. He won the lawsuit and now those who violated his rights are paying millions of dollars to Sandmann. Not only did his attackers loose a lot of money but they ended up with a black eye.