In politics, people agree to disagree by not agreeing to an appropriate bottom line. As the Bush tax cuts are extended, some emphasize a growing budget deficit; others cite expanding tax revenues while others note that as the revenues expand so do the expenditures. In fact, the latter usually outpace the former.
The Skeptical Economist helps by continuously posting the ratio of national debt to GDP. That looks like a useful bottom line -- and it has been slowly falling.