In American English, it means "conservatives don't like it". If legislation isn't to the liking of right-wing politicians and special-interest groups, or their corporate sponsors, then it stands a chance of being called a "socialist program" that "the American People won't stand for" (as if they actually gave a damn about or spoke for those people). This buzzword dates back to the antics of the early post-WWII era. It's a now-ancient FUD-word.