The Politico explains:
"Candidates who are at behind at the end reach and sometimes they overreach," McCaskill said. "This ad is a very dangerous ad because it reaches back to college... I think the ad came close to the line."
The ad was also address by Rand Paul at the debate between himself and Conway, video below H/T to Hot Air, where Paul asks Conway "Have you no decency? Have you no shame?".
Paul refused to even shake Conway's hand. Rightly so.
According to Real Clear Politics averages, Paul is ahead of Conway by 5.3 percent in the polls.