(CNN) - Call it a polling hat trick. For the third time this week, a survey of likely Iowa GOP caucus goers has Republican presidential candidate and Rep. Michele Bachmann at the top.

According to a new poll from Mason Dixon Polling and Research, 32 percent of people questioned in the survey say they are backing the congresswoman from neighboring Minnesota for the GOP presidential nomination. At 29 percent is former Massachusetts Gov. Mitt Romney, who's making his second bid for the White House. Bachmann's lead is well within the poll's sampling error.