To Roth, or Not to Roth

From Megan McCardle of Bloomberg News:

What will the tax rate on your income be when you retire — higher or lower than your current tax rate?

Hard to say, isn’t it? We’re running some substantial deficits, and we’ve made some big promises to retirees. Those obligations will have to be paid for somehow, and by “somehow,” I mean “With higher taxes on someone.” What are the chances that you’ll be that someone? Pretty high, if you save a lot for retirement.

That makes a Roth sound like a pretty good bet. But unfortunately, the same logic that suggests higher income taxes in the future also suggests that a hungry-eyed Congress might settle on all those fat tax-free retirement accounts as a way to balance the books. What Congress giveth, Congress can taketh away. Can you really count on that income being tax-free when it’s finally time to collect it?

Do you trust Congress to keep their promises?