Louis C.K. better dry clean his finest black t-shirt this week: NBC just announced the comedian will host SNL for the second time on March 29. No musical act has been selected for the date as of yet. So…JFK this time around? Nixon? A little Rutherford B. Hayes? Just kidding, Louis C.K. has to double down on his Lincoln. You’re going to mention a character getting shot twice in a sketch? Come on now. The comedy rule of threes basically demands a follow-up.