Mike Huckabee doesn't have to give up his quest for the Republican presidential nomination -- but he probably should.
The reason for this is that he's made his point that he can appeal to the Republican right-wing and maybe John McCain should consider him as a potential running mate. His continued campaigning would only serve as a distraction and fuel the opposition.
Huckabee has done some scary things these days which, if he continues, may tarnish his viability. For example, he called repeal of the Supreme Court's Roe v. Wade decision his "number one" priority.
Roe v. Wade was a horrendous abortion of years of legal precedent. But the ultimate decisionmaker in a crisis pregnancy isn't a judge or legislator and there are many other priorities more important to the nation as a whole. The economy, for one. Iraq, for another. Rebuilding our national defense, too. And, yes, securing our borders.
Mike Huckabee is a likeable guy and he's been very careful not to bash McCain. But even Mitt Romney has seen the light.
As McCain works to secure the party base, Huckabee will go from an attraction to an annoyance to a liability.