Well, now President Obama has done quite a number of things, which bring to mind other analogies, some of which lurk beneath the worship continuum. Before Roosevelt there was Herbert Hoover, and before Lincoln there was James Buchanan, both of whom share the dishonor of being ranked among the country’s worst presidents, as Nathan Miller pointed out a decade ago in a perky book entitled “Star-Spangled Men.” About Hoover, much has been written; but it is President Buchanan who presents a really interesting case.

Miller’s review suggests that presidents fail because they are clueless or spineless or both. James Buchanan was both. Among the most reviled in the heap, he exhorted Supreme Court justices to deliver what was arguably the most disastrous court decision in American history—Dred Scott v. Sanford—and in the process egregiously violated constitutional integrity and the separation of powers. Buchanan lambasted Congress for not passing the notoriously pro-slavery Lecompton Constitution that would have admitted Kansas as slave state into the Union. To get his way he resorted to political thuggery: promises of cash to his supporters and dismissal of officials who opposed him. All to no avail; Congress defeated the measure anyway. A later vote in “bleeding Kansas” resulted in the defeat of the Lecompton plan by a margin of about nine to one, a result that surprised him. Cluelessness.

And when Southern States seceded one by one, Buchanan dithered and temporized, declaring such acts unconstitutional, but unlike Andrew Jackson before him and Abraham Lincoln after him, he did nothing. Spinelessness throughout. All this from a man who believed that defusing the time bomb over slavery would rank him at the level of George Washington, a hope that goes beyond cluelessness.

This is the danger of the Obama presidency, as Barack Obama juggles a half dozen major bills along with several foreign-policy challenges, any one of which risk failure that could damage his presidency severely, if not destroy it altogether. Since the summer especially, Obama’s executive style has been carefully documented with increasing alarm by president-watchers, even those who are sympathetic to his goals. Thus, on healthcare, Mr. Obama has insisted on reconstructing the entire industry in spite of the fact that all but a minority of Americans have insurance, and by large margins are satisfied with their coverage. Ghosts of Lecompton haunt this figure.

In foreign policy, Obama has courted dictators, spurned America’s traditional allies, and curried favor with adversaries such as the Medvedev-Putin duo by caving to their objections over a missile shield in Poland and the Czech Republic—apparently in hopes that appeasing the Russian bear will bear fruit in negotiations with Iran. Such spinelessness did not go unnoticed by the Iranians, who responded with missile-firing contempt. Finally, the president’s vacillation over Afghanistan while carbon-foot-printing his way to that other Euro-Superpower, Denmark, apparently to seek advice from Hamlet on executive decision making, hardly speaks well for his quest to find the buck that stops somewhere in the vicinity of the Oval Office. It’s hard to see how old “Public Functionary Buchanan” could have done worse.

The implications of these actions seem to escape President Obama, and therein lies the chief danger to his presidency. He could take a lesson from another predecessor to a favored president, Dwight D. Eisenhower. Neither flashy nor eloquent, Ike actually had a life before writing about it and knew the world is not a global version of Mr. Roger’s Neighborhood. Further, he possessed the good judgment not to inflict ambitious programs onto a population weary of war and the previous incumbent, much like Americans in 2008 who were tired of conflict and of George W. Bush. Initial reviews of Ike’s terms in office were unenthusiastic; more recently, his stature has risen among mature scholars who do not equate presidential greatness with increased federal power.