DESPERATE “Action Alerts” land in my in-box. They’re from the American Political Science Association and colleagues, many of whom fear grave “threats” to our discipline. As a defense, they’ve supplied “talking points” we can use to tell Congressional representatives that political science is a “critical part of our national science agenda.”

Political scientists are defensive these days because in May the House passed an amendment to a bill eliminating National Science Foundation grants for political scientists. Soon the Senate may vote on similar legislation. Colleagues, especially those who have received N.S.F. grants, will loathe me for saying this, but just this once I’m sympathetic with the anti-intellectual Republicans behind this amendment. Why? The bill incited a national conversation about a subject that has troubled me for decades: the government — disproportionately — supports research that is amenable to statistical analyses and models even though everyone knows the clean equations mask messy realities that contrived data sets and assumptions don’t, and can’t, capture.

It’s an open secret in my discipline: in terms of accurate political predictions (the field’s benchmark for what counts as science), my colleagues have failed spectacularly and wasted colossal amounts of time and money. The most obvious example may be political scientists’ insistence, during the cold war, that the Soviet Union would persist as a nuclear threat to the United States. In 1993, in the journal International Security, for example, the cold war historian John Lewis Gaddis wrote that the demise of the Soviet Union was “of such importance that no approach to the study of international relations claiming both foresight and competence should have failed to see it coming.” And yet, he noted, “None actually did so.” Careers were made, prizes awarded and millions of research dollars distributed to international relations experts, even though Nancy Reagan’s astrologer may have had superior forecasting skills.

Political prognosticators fare just as poorly on domestic politics. In a peer-reviewed journal, the political scientist Morris P. Fiorina wrote that “we seem to have settled into a persistent pattern of divided government” — of Republican presidents and Democratic Congresses. Professor Fiorina’s ideas, which synced nicely with the conventional wisdom at the time, appeared in an article in 1992 — just before the Democrat Bill Clinton’s presidential victory and the Republican 1994 takeover of the House.