The latest Rasmussen Reports national telephone survey of likely GOP primary voters shows Minnesota Congresswoman Michele Bachmann fading, while Texas Gov. Rick Perry tops the field at 28 percent support and former Massachusetts Gov. Mitt Romney follows at 24 percent.

In what looks increasingly like a two-candidate race, the rest of the pack trails far behind the frontrunners. Former House Speaker Newt Gingrich registers a 9 percent, while Bachmann comes in fourth at 8 percent. That's just ahead of Georgia businessman Herman Cain at 7 percent, and Texas Congressman Ron Paul at 6 percent.

There are some signs of a narrowing gap between Perry and Romney. As Perry entered the race in August, he jumped to an 11 point lead over Romney, 29 percent to 18 percent.

Curious, though, is seeing Romney edge back up against Perry, without Perry losing much support. That means Romney is picking up support from elsewhere. Bachmann? She was at 13 percent in Rasmussen's last poll, down from 16 percent in early August.