WASHINGTON — Speculation about who would make a good vice presidential running mate for Republican John McCain ranges all the way from party also-rans Mike Huckabee and Mitt Romney to Democrat Bill Richardson. But a new Gallup survey shows the largest bloc of rank-and-file Republicans — 31 percent — are those who cannot name a candidate for the job.

The next biggest group, 21 percent, prefer the choice marked “other.”

Huckabee and Romney, who were both defeated by McCain in the Republican presidential primary race, led the pack of named choices with 18 percent and 15 percent, respectively, in the telephone survey conducted March 24-27.

Some 8 percent of 453 Republicans and Republican-leaning voters polled would like to see Secretary of State Condoleezza Rice as vice president.

She was followed by the “no opinion” category which drew 5 percentage points.

Then came three other former Republican hopefuls: Fred Thompson with 4 percent; and Ron Paul and Rudy Giuliani with 2 percent apiece.

Sen. Joe Lieberman, the Connecticut independent who has appeared at campaign events with McCain, also got 2 percent.

Former Democratic presidential hopefuls John Edwards and Bill Richardson each drew 1 percent.

Gallup said the results have a 6 percentage-point error margin.

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Photo credit: REUTERS/Jason Reed (McCain speaks at the Naval Academy in Annapolis on April 2)