If we can borrow all that new money "scot-free," will we truly reduce future expenditures on social security benefits? Or will those funds simply be diverted, either explicitly or implicitly, to finance the Medicare shortfall? Which way would you, as a bondholder, bet?As I've written before, there are a lot of nitty-gritty reasons to tackle Medicare and spiraling health costs long before we ever touch Social Security. For starters, read Jesse Taylor's post, where he worries that Bush's plan will leave seniors with only 1/3 guaranteed benefits. Sadly, that's nonsense—it will be much less than that. So long as Medicare Part B premiums rise the way they do, and take increasingly large bites out of our Social Security checks, the president's plan will effectively leave retirees with zero guaranteed benefits down the road.