Impeachment is a two part process. Johnson and Clinton only jumped through the first hoop. The second hoop is what gets you removed from office. And, regardless, I highly doubt Bush is trying to add an impeachment trial to his legacy right now.
Your semantics are skewed. Impeachment is simply the first hoop. The second hoop is a trial, not impeachment. The second hoop that you refer to is "Removal by Impeachment." Your "hoops' are two completely different concepts.