With recent polls showing Republican presidential hopeful Mitt Romney either trailing or at best tied with Rick Santorum in the Michigan primary, some Republican leaders are starting to get nervous.

One "prominent Republican senator" told ABC News senior political correspondent Jonathan Karl on Friday that "if Romney cannot win Michigan, we need a new candidate," because with such a weak nominee "we'd get killed" in the general election.
The unidentified source also expressed the opinion that neither Rick Santorum nor Newt Gingrich would be an acceptable choice, because they would "lose 35 states," and named former Florida Governor Jeb Bush as his preferred alternative.