Former Vice President Dick Cheney on Wednesday endorsed Kentucky Secretary of State Trey Grayson in the state’s closely watched GOP Senate primary.

In his announcement, Cheney emphasized Grayson’s national defense credentials and praised him as a candidate who could deal with the serious global threats facing America.

“The challenges posed by radical Islam and Al Qaeda are real and will be an on-going threat to our domestic security for years to come. 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,” Cheney said.

Recent polling has shown Grayson trailing Rand Paul, the son of libertarian champion Rep. Ron Paul (R-Texas), by 15 points just two months out from the May 18 primary. Paul has sought to paint Grayson — a protégé of Senate Minority Leader Mitch McConnell (R-Ky.) — as just another political insider while Grayson has attempted to make the case that Paul, an eye surgeon, is simply riding the political network built by his father. On Tuesday, Paul was able to tap into that network to raise more than $260,000 through his one-day “Give Me Liberty” online fundraising event.

“I’m a lifelong conservative, and I can tell the real thing when I see it,” Cheney said in his statement. “I have looked at the records of both candidates in the race, and it is clear to me that Trey Grayson is right on the issues that matter — both on fiscal responsibility and on national security,” Cheney said.

The eventual GOP nominee will face the winner of the Democratic primary that features Lt. Gov. Dan Mongiardo and Attorney General Jack Conway.