Ha!
You don't oppose it, you just weigh in when you don't know what you're talking about, specifically misrepresent the stated purpose of the march, call the marchers untruthful, say the march is against the common good, describe the marchers as partisan hacks, say the march is stupid, say the marchers' focus is a fraud, described the marchers as 'crazy, divisive, counter-productive' and having no point whatsoever, and say the marchers are inherently dishonest, but heavens no, you don't oppose it.