Well firstly nobody thought that a ban would come out of this process. Secondly, there are some people whose behaviour falls well short of acceptable and any community should have the right to exclude them.
Whether or not you thought the petition would be successfull is irrelevent. Support of an idea is support of an idea. If I where to publicly support everyone having the same standard of living, regardless of their contribution (or lack there of), it would be fair to say that I am a Communist. If you support a Facist petition, one could surmise that you are a Facist. I, however, give you the benifit of the doubt, and merely attack your action, not make a blanket statement about your political leanings.
You said, "...there are some people whose behaviour falls well short of acceptable and any community should have the right to exclude them." And yet you have a problem with Trump suggesting just that. Typical leftwing double standard.