Later. You don't cut deficits during depressions. What you do is that you spend the surplus you've accumulated during the good years. Unless you elect George W. Bush and run a huge deficit during the boom years. Then you're just screwed, and that's that.
But I guess worrying about it is something you can start doing right now. It is worrying.
Uh, with a rare exception when the Congress restrained spending 1995-2000, there was no surplus in the federal treasury, whether the President was Republican or Democrat!