Not only is it workable and viable, it's been done before twice.
Under President Eisenhower, we had Operation Wetback and Operation Wetback II where millions of illegals were rounded up and deported.
As for saving the GOP, the more Romneys, Ryans, McCains they deliver the less I care.
Deporting 20-30 million is not happening. Think about it. It would kill the republican party.
Deportation is acceptable with those who have come here of their own volition, not those who were raised here of no fault of their own