Robert A. Dahl, in Politi-cal Science Quarterly (Fall 1990), 475 Riverside Dr., Ste. 1274, New York, N.Y. 101 15-0012.

When Ronald Reagan swept into the Oval Office in 1980, politicians and pundits fell over one another declaring his 50.9 per- cent victory a "mandate" to govern-just as they had upon the election of most pres- idents chosen during this century. Indeed, writes Dahl, a Yale political scientist, "it has become commonplace for presidents and commentators alike to argue t...