Ya know, many American citizens have died over the years to give people in this country the right to free speech and the right to assemble and what not. I'm glad we live in a country that allows peaceful demonstrations and doesn't just round them up and shoot them because their ideas don't mesh with the government.
However, stopping traffic is not peaceful. It interferes with peoples lives and hurts their arguments. All of these protesters should be arrested for that reason and that reason only.
I don't agree with their protest but they have the right (under our constitution) to peacefully protest.