Ben Stein says FBI's Got Nothing on Brett Kavanaugh

Ben Stein doubled down his support for Brett Kavanaugh ... saying the FBI's sexual assault investigation against him came up empty and it's time to drop it.

We got the 'Ferris Bueller' actor at LAX Thursday and he sang his fellow Yale alumnus' praises amid a new FBI report that reportedly concludes there is no corroboration to Dr. Christine Blasey Ford's allegation Kavanaugh sexually assaulted her at a party 36 years ago.

Remember ... Stein told us last month Ford's allegations are a "f***ing disgrace" and wasn't buying Ford's story. So, it's no surprise he's swinging hard for Kavanaugh with this weekend's Senate confirmation vote looming.

But, watch as our guy again goes head-to-head with Ben and tells him the FBI's investigation is incomplete because, among other things, it failed to interview Ford, Kavanaugh and several key former classmates.