as if conservatives before trump haven't been salivating at the thought of killing the USPS

I know conservatives in many countries favour certain things being privatized, but somehow I don't get the sense the top-level comment just meant 'fuck anyone who favours privatizing anything.' I don't know the specific details about the American post office. If that's been an ongoing debate, it's not one that I've heard much about.

This is how conservatives work. . . . pushed the same heinous policies while using figurehead presidents to pin all their blame on and then run away from the label while continuing the same exact policies

This is either an insane generalization, or you're speaking only to a fairly narrow range of people and thus shouldn't be trying to map your observations onto 'conservative,' one of the broadest political terms ever.