Well establishing residency includes changing your voter registration. At least it does for the rest of us citizens. So your telling me that Tom Delay is going to change his address back on the day before the election? What would be the purpose of registering in Virginia if he planned on doing that. Its stupid. If he is playing a game, then that isn't a very good representative.
I'm not saying that he will change his address back; I'm saying that he could change his address back. And it doesn't matter what his purpose would be, because the Constitution does not include an "unless Tom DeLay doesn't plan to" caveat. As for getting of the ballot, Tom DeLay can still withdraw any time he feels like it. He didn't try to withdraw; he tried to declare himself ineligible. He can do that too, if he really wants to, but he'll have to actually do one of the things that makes him ineligible under Texas statute.