You may be right about the origin of "the right side of history", but the phrase has become popular enough that you can't use it to pin down the speaker's ideol

You may be right about the origin of "the right side of history", but the phrase has become popular enough that you can't use it to pin down the speaker's ideology. I think most people use it to mean that their ideas will be commonly accepted in the future. Whether their perceived future is a communist utopia or a libertarian thunderdome is irrelevant.