Both visions are unrealistic. Given an aging population — which boosts Social Security and Medicare spending — government is automatically expanding. Since 1971, federal spending has averaged 21 percent of the economy (gross domestic product); just continuing present programs could easily raise that to 28 percent of GDP by 2021. The liberal-reactionaries can’t smoothly finance that. In 2011, the deficit is already twice the entire defense budget. The richest 10 percent already pay 55 percent of federal taxes. The blanket embrace of all benefits for the elderly — no matter how rich — will require much higher taxes or steep cuts in other programs, including those for the poor.

The conservative-radicals are no better. Since 1971, federal taxes have averaged about 18 percent of GDP. There is no believable plan to reduce federal spending below that level, even with sizable cuts in Social Security and Medicare benefits. So promises of more tax cuts either border on dishonesty or imply huge unspecified spending cuts that would devastate national defense, states and localities, and the poor.

A dilemma of democracy is the difficulty of making changes that, though essential for society’s long-term well-being, are unpopular in the short run. That describes today’s budget deadlock. To be sure, not all conservatives and liberals have become radicals and reactionaries. But many have. If we applied true labels to them — reactionaries and radicals — we would clarify the debate and compel them to deal with the world as it exists, not as they imagine it. Dream on.