ABC News’ Teddy Davis reports: Remember when Rudy Giuliani and Ron Paul used to spar in the 2008 Republican presidential debates? Well, the feuding is not over. Giuliani is now wading into the Kentucky GOP Senate primary by endorsing Secretary of State Trey Grayson, the Republican running against Ron Paul’s son. “Trey Grayson is the candidate in this race who will make the right decisions necessary to keep America safe and prevent more attacks on our homeland,” said Giuliani in a written statement. “He is not part of the ‘blame America first’ crowd that wants to bestow the rights of U.S. citizens on terrorists and point fingers at America for somehow causing 9/11.” To paint Rand Paul has part of the “blame America first” crowd, Grayson’s campaign has put together a web video highlighting statements in which Rand Paul – and Ron Paul – suggest that American occupation of Islamic lands contributed to the attacks of 9/11. Watch it HERE. Giuliani’s endorsement of Trey Grayson is the second time in recent weeks that the former New York mayor has engaged in political payback. Earlier this month, Giuliani backed Marco Rubio over Charlie Crist in the Florida Senate race. Read more HERE.