1. Now that everyone is tired of listening to that idea, why don’t you stop talking about it? You have run it into the ground.
2. I’m going to push this idea with the boss until he accepts it, even if I have to run it into the ground.

Compare to: beat a dead horse. Beat a dead horse means to talk about a topic or idea that cannot succeed (it’s dead), whereas run something into the ground means to talk about a topic or idea that may be viable, but to do so to excess.