The general-election polls show Romney 12 points behind Hillary Clinton and McCain tied with her. If she's the Democratic nominee, McCain has two big advantages: He can get Hispanic voters (thanks to his sponsorship of immigration reform) and he can attract Democrats and Independents who backed Obama and are turned off to Hillary as a candidate.
Romney, without any appeal to Latinos and not much to moderates or Independents, would be a far easier opponent for the Clintons to take on.
Poll: Only 4% of U.S. Adults are Newly Insured, Half Choose Obamacare Alternative | Sarah Jean Seman