Former Sen. Rick Santorum, Sen. Ted Cruz of Texas and Sen.
Roof credited the group's website with alerting him to the problem of "brutal black-on-white murders," part of an evolution that he said led him to the attack. Holt's group says it opposes "all efforts to mix the races of mankind ... and to force the integration of the races."
In a statement posted online, Holt said the group did not condone Roof's actions. The council "does not advocate illegal activities of any kind, and never has," he said in the statement.
The donations are at the center of the latest in a series of race-related debates that have consumed the campaigns in the wake of the Charleston shooting. GOP candidates also have found themselves under pressure to address a growing call to remove the Confederate flag that flies on the grounds of the South Carolina Capitol in Columbia, about 115 miles from Charleston.
Former Republican presidential nominee Mitt Romney was among those who joined that push Saturday, saying that many see the Confederate flag as a "symbol of racial hatred." He called for its immediate removal from the Capitol grounds. "Remove it now to honor #Charleston victims," he wrote on Twitter.
For Republicans in particular, the issues present an uncomfortable viewpoint that carries the risks of turning off some conservative white voters.
The contributions were first reported by the Guardian newspaper Sunday. Cruz's campaign told the paper it would return $8,500 it had received from Holt. The Paul and Santorum campaigns said they would donate the contributions they'd received to the Mother Emanuel Hope Fund for the shooting victims' families. Neither campaign would disclose the total each had received.
The donations to the three presidential hopefuls were just a small slice of the tens of thousands -- $65,000, according to the Guardian -- Holt has contributed to Republican candidates in recent years. The list includes Romney’s 2012 presidential campaign; former Minnesota Rep.
It was not clear whether these candidates knew of Holt's beliefs. Paul's campaign would not comment on how much money it had received from Holt, whether it was solicited and whether the senator had ever met Holt.
In a statement, Santorum condemned Holt's statements.
"I abhor the sentiments Mr. Holt has expressed. These statements and sentiments are unacceptable. Period. End of sentence," he said.
Staff writer Lisa Mascaro contributed to this report. For more political coverage, follow @khennessey