Why isn't Huckabee throwing in the towel?

WASHINGTON — A day after John McCain appeared to have nailed down the Republican presidential nomination, Mike Huckabee clung Friday to the faint hope that he could snatch it away.

He gamely pleaded for support at "Huckabee for President" rallies in Wichita, Topeka and Kansas City, Kan.

But for many who have watched Huckabee rise to the top tier of candidates only to see McCain emerge as the presumptive nominee, the question has become: Why keep going?

"I still believe that we can win," Huckabee told listeners at one of his Friday gatherings.

Few share that view. Many say that Huckabee's only rationale for staying in the race is to gain leverage for the vice presidential spot.

McCain has more than six months -- a political eternity -- to choose a running mate for the Republican National Convention to formally nominate, along with himself, in early September. The campaign climate that will dictate the Arizona senator's choice could change radically by summer; at the least, it will be influenced by the outcome of the Democratic presidential race between Sen. Hillary Rodham Clinton of New York and Sen. Barack Obama of Illinois, which shows no sign of ending soon.

If, as many suspect, Huckabee is continuing his presidential bid largely to build momentum as a vice presidential prospect, he also must deal with a counter campaign.

Just hours after former Massachusetts Gov. Mitt Romney's exit from the GOP race on Thursday effectively handed the nomination to McCain, Huckabee's critics intensified efforts to deny him a spot on the ticket. The opposition stems largely from his record as governor of Arkansas from mid-1996 through 2006.

"Clearly, an economic liberal like Mike Huckabee will be unacceptable to a majority of Republicans," Pat Toomey, president of the Club for Growth, a conservative advocacy group, said in a statement. On Friday, Toomey released his roster of preferred vice presidential picks, which was led by South Carolina Gov. Mark Sanford.

David A. Keene, chairman of the American Conservative Union, said Huckabee's record on taxes and immigration would only worsen McCain's friction with conservatives if he were on the ticket.

One Republican leader openly offered himself as a vice presidential candidate: Former House Speaker Newt Gingrich told ABC News -- in response to a question -- that he would accept the honor, but doubted McCain would offer it to him.