Former Vice President Dick Cheney endorsed Kentucky Secretary of State Trey Grayson today, calling him the “real deal” in the Republican race to succeed retiring Sen. Jim Bunning (R-KY). But it was clear that Cheney’s endorsement was as much a statement against Grayson’s primary opponent, Bowling Green eye surgeon Rand Paul.

“The challenges posed by radical Islam and Al Qaeda are real and will be an ongoing threat to our domestic security for years to come,” said Cheney in his endorsement. “We need Senators who truly understand this and who will work to strengthen our commitment to a strong national defense and to whom this is not just a political game.” This is a not too thinly veiled shot at Paul, the son of the antiwar Texas congressman and 2008 Republican presidential candidate Ron Paul.

Grayson has hit Rand Paul on foreign policy and the war on terror throughout the campaign, but national security conservatives were slow to awaken to Paul’s rise in the polls. Now Paul is the frontrunner for the nomination and the Politico reported last week that the alarm is being sounded outside Kentucky. A senior Cheney aide reportedly sent out an email to various high-profile hawks warning, “On foreign policy, [global war on terror], Gitmo, Afghanistan, Rand Paul is NOT one of us.” Paul has responded in part by moderating some of his views, such as on military tribunals and Gitmo. It remains to be seen whether this will impact the May 18 GOP primary, or whether it will have as much influence as Cheney’s endorsement of Sen. Kay Bailey Hutchinson (R-TX) over Texas Gov. Rick Perry.