The beleaguered U.S. Senate campaign of Rep. Todd Akin (R-MO) was hit with another discouraging development Friday evening, with a new poll showing him trailing Sen. Claire McCaskill (D-MO) by 9 points while being viewed unfavorably by a majority of likely Missouri voters.

According to the survey, conducted by Mason-Dixon on behalf of the St. Louis Post-Dispatch and St. Louis-based CBS affiliate KMOV-TV, McCaskill leads the embattled Akin among likely voters, 50 percent to 41 percent. That’s a sharp reversal from Mason-Dixon’s poll of the race a month ago before the Republican primary, when Akin held a 5-point advantage over the Democratic incumbent in a hypothetical match-up.

McCaskill’s newfound lead can be largely attributed to an enormous gender gap. The poll shows the first-term senator with a massive lead over Akin among women voters, 55 percent to 37 percent. A month ago, McCaskill held a mere 1-point edge over Akin among women.

he poll, the first public live telephone survey since Akin’s controversial remarks last Sunday regarding rape and abortion, provides further proof of the mounting political damage for the congressman. A snap poll conducted by Democratic-leaning Public Policy Polling (PPP) roughly 24 hours after Akin’s comments showed the race still neck-and-neck. Meanwhile, a poll later in the week by Republican-leaning Rasmussen Reports showed McCaskill opening up a 10-point lead over Akin.

The two polls, both automated, created a surreal situation in which neither party wanted to claim the lead. Republicans accused PPP of cooking a poll designed to persuade Akin to remain in the race, while McCaskill called shenanigans on Rasmussen. The non-partisan Mason-Dixon poll may provide some clarity to the race, long considered one of the surest pick-up opportunities for a Republican Party desperate to take back the majority in the Senate.

Friday’s poll shows that 47 percent of Missouri voters think Akin should withdraw his nomination, including 50 percent of his own supporters. Thirty-seven percent believe Akin should remain in the race. McCaskill supporters are divided on the question: 40 percent believe her Republican challenger should end his campaign, while 44 think he should stick it out.

h/t: Tom Kludt at TPM