Which amendment will Keyes tackle next?

So, how about a little contest to guess which Constitutional amendment Keyes is going to tackle at his next press conference? (And seriously, it seems obvious to me that he called this press conference because he hadn't been in the paper much recently.) We've covered the 1st, the 2nd, 10th (federalism), 16th (income tax) 17th (election of senators). So, about the 18th (prohibition) and 21st (and its repeal)? Although Keyes says he likes an occasional drink, it might be fun to see him tackle prohibition. Or there's the 19th (equal protection) or the 13th (banning slavery)? I could see him tackling the 22nd (term limits for the Presidency) with that whole "as the founders intended" argument. Any other guesses?