Actor Topher Grace was excited to find out he was playing former Ku Klux Klan leader David Duke in Spike Lee s new movie BlacKkKlansman, but getting ready for filming after snagging the role was a different story.

It was just the worst month of my life, Grace told Vulture at the Cannes Film Festival on Tuesday, in reference to studying Duke.

I listened to a lot of his radio show, I watched Donahue because he was on that a lot and I read My Awakening, his autobiography, which is horrible, he siad. Its like Mein Kampf.