Rick Perry -- Not Michele Bachmann -- is Mitt Romney's Main Rival

Mitt Romney, the former Massachusetts governor who is currently the front-runner for the Republican presidential nomination, is hearing footsteps according to a new poll released on Monday, and they belong to Gov. Rick Perry of Texas.

The new poll from Rasmussen Reports showed Romney leading the pack with 22 percent, with Perry --who has not officially entered the race --in second with 18 percent. U.S. Rep. Michele Bachmann, who has been gaining in the polls during the summer but has been surpassed by Perry in recent ones, took third with 16 percent. U.S. Rep. Ron Paul of Texas came in fourth with 10 percent with businessman Herman Cain in fifth with 9 percent. Former U.S. House Speaker Newt Gingrich was in sixth place with 6 percent.

The rest of the field continued to struggle in the poll. Despite high expectations for their campaigns, former Gov. Tim Pawlenty of Minnesota came in seventh with 3 percent. Jon Huntsman, the former governor of Utah and ambassador to China, continued to flop, taking 2 percent in the Rasmussen poll. Four candidates -- former Gov. Gary Johnson of New Mexico, former Gov. Buddy Roemer of Louisiana, former U.S. Sen. Rick Santorum of Pennsylvania and U.S. Rep. Thad McCotter of Michigan -- took less than 1 percent in the poll.

The poll of 1,000 likely Republican primary voters was taken on July 28 and had a margin of error of +/- 3 percent.