Then as now, the Republican primaries opened with a bang, when George H.W. Bush upset Ronald Reagan in the Iowa caucuses. By late February, this loss would lead to Reagan’s firing of his campaign manager, John Sears, in a disagreement over strategy.

Then, as now, Republicans feared that an unhappy contender might bolt the party to mount an independent campaign. In 1980, that was liberal John Anderson, not libertarian Ron Paul. Mr. Anderson did end up running as an independent, whereas Mr. Paul will likely be constrained by the effect a third-party run would have on the future prospects for his Republican son, Kentucky Sen. Rand Paul.

Then as now, the chattering classes wondered aloud whether a candidate who could win the Republican nomination could prevail against President Carter in November. On March 1, former President Gerald Ford amplified that view when he told a New York Times reporter, “Every place I go and everything I hear, there is the growing, growing sentiment that Governor Reagan cannot win the election.”