You mean voting third party, or threatening to, has an effect on politicians' behavior? Better not let that word get out...
Watch, they will call for a yea or nay vote. Roberts will be confirmed and everyone will have cover. Those that need to hear "I voted against", will hear it and the other part of the party will hear that "he appeared to be level headed so I voted with the majority."
I believe other judges have been voted in this way.