WASHINGTON -- Todd Akin was effectively tied with Sen. Claire McCaskill, 44 percent to 43 percent, in a poll released Monday night by the Democratic firm Publicy Policy Polling. That's little different than PPP's last poll in May, which found Akin leading 45 percent to 44 percent.

The new survey, conducted from 6 p.m. to 9 p.m. Central time, found that while 75 percent of Missouri voters thought that Akin, a GOP congressman from Missouri, was inappropriate in his comments Sunday about "legitimate rape," they still planned to vote largely among party lines.

Only 6 percent of the Republican women polled said they planned to vote for McCaskill. McCaskill led by 10 percentage points among all women, while Akin led by 14 points among men.

The full extent of the fallout from Akin's comments is still difficult to determine as calls for his withdrawal from the race mounted Monday. As HuffPost's Mark Blumenthal notes:

Most pollsters call for several days in order to contact hard-to-reach respondents, and many believe that tracking polls conducted in the immediate wake of a major development can produce fleeting "bumps" in opinion that quickly recede.

PPP polls have consistently shown the Missouri race as slightly more competitive than other polls.

The PPP poll used automated calls to survey 500 Missouri voters. It has a 4.4 percent margin of error.