ubiq, you are correct that with the passage of time the official political conservatism position on moral issues weakens and is dragged leftwards as the political liberals effectively move even further left. So what was previously the position of the left becomes that of the right, while the left moves to the position of what was previously espoused by the far left.
The same phenomena occurs on other issues such as women in the military. It wasn’t that long ago that American conservatives opposed women in the military. As the left successfully pushed further integration the conservatives held the line in opposing women in combat positions. Now I don’t see them even offering nominal opposition to that much.
The moral degradation with time is easily visible to anyone with an eye on the past.