In his speech about the budget today, Barack Obama said that we couldn't "afford" tax breaks (for the wealthy, of course -- to him, they get all the tax "breaks.")
A tax "break," a tax "cut" -- whatever you want to call it -- means that people get to keep more of their own money. To most of us, that translates to "take-home pay." So his point of view is that letting Americans keep more of their own money is an expense. To him, to Democrats, to the government.
Your paycheck is a bill the government has to pay, a bill Obama thinks the government can't afford..