I keep seeing this posted here, and I don't know where people get this idea that comeback implies that you were once ahead. It's not true. Comeback means that you were behind, and came back to win. That's all it means. You can have a comeback in a football game from being one point behind or 27 behind. Either way, it's a comeback, and you do not need to have ever been leading. Ask Frank Reich or Joe Montana.
Can Bush come back? Hell no. He's at 3, needs to beat whoever is in first. Trump is in first, at over 40 or so. It will never happen. Bush will only continue to sink.
Who the hell said anything about leading? Does somewherte mean ahead? I think you see what you want to see.