It's a good topic. If I were to pursue it, I'd come right out with that argument, that people don't bother to pick anyways, so we may as well leave it up to the professionals; after all, everybody seems to be cool with that on the State level.

You want a dual ending, tho. If people don't rise to their own defense, you need to propose some other Amendment, maybe with "graduated voting" (i.e. you can only vote for President at first, then Congress if you voted for President last year, etc.) or some such -- and if people do rise to their defense, asking them how many are registered to vote and how many voted in the last off-year Senatorial election. The trick will be to display frustration and disappointment, rather than jerkishness.