(CNN) - It's one of the basics of campaign communication: the conference call with reporters - where normally flacks would issue updates about events and reiterate talking points from the trail.
But Thad Cochran's campaign really could have used a mute-all function on its phone session with reporters Wednesday afternoon, as the call careened into a borderline racist verbal melee.
Supporters of Mississippi state Sen. Chris McDaniel inundated Cochran campaign adviser Austin Barbour with questions, before one unidentified caller pivoted along racial lines.
"Quick question," began the caller. "Since black people harvested cotton, why is it OK to harvest their votes? Why is it OK to harvest the votes of black people?"
At first, Barbour paid no mind to the question.
When the caller again asked a similar question, the normally genteel campaign hand snapped.
"Sir, I don't know where you're calling from, but I'm happy to address any question, no matter the lunacy of it," Barbour said.
The Cochran campaign convened the call to push back against McDaniel's claim that the incumbent won last week's runoff election by illegally wooing Democratic and African-American voters. (Cochran himself was not on the call.)
The inquisitor didn't relent, however, asking again, "Why did you use black people? Why did you use black people to try to get Cochran elected when they're not even Republicans? You're treating them as if they're just idiots, that they'll just vote for Cochran just because they're black."
Having apparently heard enough, Barbour hung up.
From there, the call morphed into a chat-room of sorts, those remaining on the phone questioning repeatedly wondering if this was somehow President Obama's doing before playing soundboard clips of the commander-in-chief.
The sudden influx of non-media members onto the call could potentially be linked to a conservative blogger.
Charles Johnson, the political blogger who has accused the Cochran campaign and other state lawmakers of violating Mississippi election law, tweeted the details of the conference call - including the dial-in number and the passcode - to his nearly 6,000 followers shortly before the call began.
Thursday the McDaniel campaign put out a statement that did not address the racial comments.
"With the revelation of still more allegations of criminal misconduct surrounding Cochran's effort to drive ineligible voters to the polls, it's no wonder Cochran's staffers told Mississippians seeking electoral integrity to 'shut up.' Senator Cochran's campaign is in a state of wild disarray, and Sen. Cochran should return to Mississippi and take control of his campaign by addressing the allegations of criminal misconduct surrounding his campaign's strategy of pushing ineligible voters to the polls on June 24," said McDaniel campaign spokesman Noel Fritsch in a statement
CNN Politics Executive Editor Mark Preston contributed to this report