Here's a question you've probably had: Why are the Bush tax cuts expiring in the first place?

Clive Crook at the FT has the answer:

What a commentary on the US approach to tax policy. The tax cuts are due to expire in the first place only because the Bush administration was cooking the books. The idea was to disguise the cuts’ long-term cost, which is colossal. Making them permanent would cost nearly $4,000bn over 10 years. The Republicans always wanted the changes to be permanent. The sunset provision was just a feint to make them look affordable.

Democrats are no better at playing budget games, notes Crook:

Democrats deplored the tax cuts as reckless – which they were – yet want mostly to preserve them. The middle-class part of the tax cuts, which they like, account for roughly three-quarters of the forgone revenue. Talk about having it both ways. Barack Obama organised his election campaign around this position. He complained of fiscal irresponsibility with one breath, then promised even lower taxes for most Americans – households making less than $250,000 a year, some 97 per cent of the total – with the next.

A similar contradiction might be seen with the healthcare bill, and the Democrats' promise that it would be a budget reducer, a goal accomplished by pushing other decisions down the road.