system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 exactly what Obama letting Bush's tax cuts expire means. 

I've always found myself out of the loop, politically speaking. What does this mean?

EDIT: I don't know. I just don't understand politics I guess. I read an answer that kind of makes sense and then someone else tells that person how they're an idiot and wrong and explains why they're wrong and I'm back to square one.
gpt
Back in 2001 and 2003, George Bush signed in a bunch of tax cuts that would last ten years. The cuts included reducing all five of the then-current tax brackets, as well as making a brand new super-low tax bracket for low-income earners. He also signed in a bunch of corporate tax cuts. He expanded deductions and credits on a variety of items. About one-third of the tax cuts went to the top 20% of the taxpaying population; about two-thirds went to the rest.

Now, in 2012, unless Congress does something, *all* of those tax cuts, plus the Obama tax cuts of 2009-2010, will all expire simultaneously. In addition, spending will be reduced on both the defense and nondefense budgets. These last two pieces are due to a legislative deal signed in 2011.

If all of those things happen at once, it would be a really big "fiscal shock." Taxes would go up, government spending would go down, and aggregate spending would probably fall. This would, in the absence of Federal Reserve action, cause a medium-sized recession.