It's an opportunity to dissuade them from Paul Ryan's big government expansion, 2040 is irrelevant, it increases spending over the next ten years. Since it's not Ryan signing off on budgets, and Congress doesn't have to tie itself to anything, it'll surely increase by more than that. (Especially since Romney has done away with half of it or more.)
It's bad enough the ticket has a big spending Massachusetts Liberal who created ObamaCare, supported abortion and is against full gun rights on top, but they also have the TARP-supporting, Medicare Part D supporting, budget busting, entitlement ignoring Paul Ryan on the bottom of the ticket.