Tim Pawlenty and U.S. Rep. Michele Bachmann slipped in a new CNN presidential poll released Thursday, both falling further behind former Massachusetts Gov. Mitt Romney.

Minnesota’s former governor was the top presidential pick of 2 percent of respondents, down from 3 percent in mid-July. Bachmann slipped to mid-pack with 7 percent, tumbling from 12 percent in July.

Romney led with 17 percent, up 1 percent since last month.

The poll comes two days before the Iowa straw poll, which could become a make-or-break moment for several fledgling GOP presidential campaigns.

In a head-to-head matchup, Bachmann loses to President Barack Obama 51 percent to 45 percent, according to the poll. Obama and Romney are in a dead heat, with the president getting 49 percent and Romney winning 48 percent. CNN did not test Pawlenty against the president.

Among those who identified themselves as Republicans, Pawlenty got just 1 percent.

Only 4 percent of women preferred Bachmann.

CNN’s polling outfit, ORC International, interviewed 1,008 adults between Aug. 5-7. The poll has a margin of error of plus or minus 3 percent.

Click here for poll results and crosstabs.