A lot of times people get escorted out of events for their own safety/good. People are going nuts about this but it's really a non-issue IMO. Political rallies never tolerate disruptions, and right or wrong this woman came to the rally to cause a scene and make a statement against Trump. If someone went to a Hilary rally with some kind of anti-Hilary sentiment on their shirt, and people started booing them and causing a scene, that person would be ejected as well.
Trump is scaring a lot of people, because they never thought he would gain so much traction and be an actual threat to the presidency, so they are constantly trying to discredit him and pin the scarlet R on his chest. Trump's muslim ban, while it's something I don't fully agree with, is echoing the sentiment of MILLIONS of Americans, and it's not coming from a place of hate, of "hey lets stick it to brown people". It comes from a place of fear, a fear of importing radical terrorists who's main goal is to kill as many civilians as possible. And that fear isn't completely unfounded - anyone who thinks there are no ISIS members/supporters coming over among these tens of thousands of refugees is being naive.