By accepting the endorsement of the Reverend John Hagee, an influential Texas televangelist, Republican presidential candidate John McCain risks alienating Catholic voters.
Hagee, the founder and national chairman of Christians United for Israel, has referred to the Roman Catholic Church as a "false cult" and "the apostate church."
McCain said Monday that he does not agree with some of Hagee's past comments.
But Catholic League President Bill Donohue says McCain should follow the example of Democrat Barack Obama, who said he would "reject and denounce" any support from Nation of Islam leader Louis Farrakhan.
In a statement Monday, Hagee said he has "great love for Catholic people and great respect for the Catholic Church," but has always criticized Catholic and Protestant anti-Semitism.