They claimed that supporters of conservative McDaniel had connections to the Ku Klux Klan and that McDaniel had a 'racist agenda.' They also warned that black Democrats 'could lose food stamps, housing assistance, student loans, early breakfast and lunch programs and disaster assistance' if he were to become the Republican U.S. Senate nominee.

'Vote against the tea party. Vote Thad Cochran,' one ad said. 'If the tea party, with their racist ideas, win, we will be sent back to the '50s and '60s.'

MailOnline has learned that 'Citizens for Progress' is tied to a longtime Democratic political operative who was paid $44,000 to run racially explosive 'robocalls' in the same race.

A political action committee founded by former Republican National Committee chair and former Republican Gov. Haley Barbour made those payments.

The calls were placed in predominantly black and Democratic regions of the state during the final days before Tuesday's runoff, according to a political operative in Mississippi.

Mitzi Bickers, an Atlanta pastor and former president of the Atlanta school board, used the same nonexistent group name — 'Citizens for Progress' — in a 2013 campaign for a local sales tax proposal.

After it was reported that Bickers filed a fraudulent financial disclosure report related to the campaign, she resigned her post as a senior adviser to Atlanta mayor Kasim Reed.

The political 'super PAC' that paid her to run the robocalls is called Mississippi Conservatives, according to National Review.

Haley Barbour, the former governor, founded the PAC, which is now run by Henry Barbour, his nephew.