For a wonder, the USSC, in a unanimous decision (and a rare moment of sanity), overturned the MA SJC.
And that ruling applies as much to this event as it does to the St. Paddy's Day parade. This decision, along with the ruling on the Boy Scouts, are critical protections that we as conservatives have to keep left-wingers from forcing their way into our midsts if we don't want them.
However, that also means that the leftists can exclude US.
I think you hit the nail on the head. If these gay groups were trying to stop people from protesting on the corner, that's one thing. However, it looks like all they're trying to do is exclude these people from marching in their parade. I don't have a problem with that.