But that assumes he can actually win primaries. He isn’t the “best choice” if he loses the election.
It’s fine to say “Santorum has no chance to win, so Newt is the best choice”. But if Newt loses Florida, how can you say he is the one who can win?
Newt has already won a primary and will energize the (real) conservative base. Rick Sanctimous will not gain broad appeal, even if he is able to score some points. At some point, he needs to check his ego at the door and have a sober look at where his campaign is going and what the consequences of continuing are.
Romney is a loser as a nominee. He is the AstroTurf candidate, with no grassroots support. Many of us will refuse to vote for him in the general.