Former Minnesota Gov. Tim Pawlenty, Mississippi Gov. Haley Barbour, Ambassador to China Jon Huntsman, former Sen. Rick Santorum (R-Pa.) and former New Mexico Gov. Gary Johnson all come in under 5 percent in the poll.

Real estate mogul Donald Trump, meanwhile, was volunteered as a choice by enough respondents to garner 1 percent in the Gallup poll.

The poll surveyed 1,082 Republicans and Republican-leaning independents and has a margin of error of plus or minus 4 percentage points.

So far, Pawlenty is the only top-tier Republican to officially form a presidential exploratory committee. Romney and Gingrich are widely expected to follow him into the race. 

Bachmann is leaning toward a 2012 run and will form an exploratory committee by June at the latest if she decides to get in.