But one of the most basic principles of economics is that when an economy is anemic, governments should use deficit spending as a fiscal stimulus, even though that means an increase in debt. If Senator Rubio believes that the response to a weak economy is to slash spending, he is embracing the approach that Herbert Hoover discredited 80 years ago.

Republicans are correct that debt matters and that we need to address America’s long-term deficits. That means trimming entitlement programs and reducing the rise in health care spending that is eroding their viability; we also probably need some tax increases. But while our long-term need is to rein in deficit spending, our short-term need is to boost it. That’s why sensible budget plans involve a short-term stimulus combined with long-term trims that take effect when the economy is healthy again.

The Republican plan to address debt right now, in an economic trough, echoes the horrendous mistake Japan made in the mid-1990s just as it was emerging from its own deep recession. Japan collapsed right back into what became its “lost decade” and now realizes that it should have nurtured a recovery before addressing its debt problem.

I was living in Japan then and referred to the prime minister on the front page of The New York Times as “Herbert Hoover” Hashimoto. So it only seems fair to refer now, if the shutdown occurs, to the current speaker of the House as “Herbert Hoover” Boehner.

Imagine how disastrous it would be if the Republicans shut down government for any length of time. Unpaid federal employees would cut back on shopping. Some would miss house payments. Family members might drop out of college. The I.R.S. might not be able to deliver some tax refunds. Small businesses would stop getting government loans. In sum, after the Democratic stimulus, we would have the Republican drag.

Republicans are also threatening to refuse to raise the government debt ceiling. By July, that could mean a default on U.S. government bonds. The Federal Reserve chairman, Ben Bernanke, says that would be “catastrophic,” and Treasury Secretary Tim Geithner warns that we could see “a financial crisis potentially more severe than the crisis from which we are only now starting to recover.”

All this seems mind-bogglingly petty and pusillanimous. If members of Congress shut down government and trigger a new financial crisis, then they shouldn’t just have their own pay docked. They should also learn the discipline of a market economy and be fired by the public that they are betraying.