One of the issues in the increasingly bitter and ugly campaign is a rape case involving a curling iron that Coakley, as attorney general, did not aggressively prosecute.
At a recent Brown rally, someone in the crowd shouted, "Shove a curling iron up HER butt." Brown seemed to smile and nod his approval.
Watch the video and see for yourself:
On Monday, a spokesman said Brown never heard the remark in question.
"He emphatically said he did not hear it," a campaign staffer said. "There was a large crowd," and he wasn't looking at anyone in particular.
President Obama campaigned on Sunday for Coakley in an effort to mobilize Democrats. Obama has a personal stake in this -- Brown promises to vote against health care reform if he's elected, and that could doom the entire bill.