There is actually some logic behind Romney's statements:
1. After Tuesday everything is going to be pointing to 2016 eleccions, and GOP can't win the White House without reaching to the immigrant community.
2. If GOP pass their own bill they won't have to share the credit with democrats, and democrats will be seen as the party of broken promises.
3. The only way they could beat Hillary is with a combination of passing CIR and nominating a centrist like Jeb Bush.