One possible outcome could be one where there is no agreement for a suitable bill on immigration prior to the November general election thus getting Congress over the hump and then we end up with an atrocious piece of legislation right after the elections with at least two more years for voters to forget about a sell-out. All I say is be careful for what you wish for as you may get it and then some. IMO we'd be better off pushing for an "ENFORCEMENT ONLY" piece of legislation - pull out all the stops - now!
Please name said "viable" third party, and candidates would be even better, for November. Sorry, but as bad as you think the GOP are on this issue, you already have people like Tancredo and Sensenbrenner (sp?) in the House - you really want to turn them out too?