On the Republican side, Mike Huckabee's candidacy rests on serial non sequiturs: I am a Christian, therefore I am a conservative, therefore whatever I have done or propose to do with "compassionate," meaning enlarged, government is conservatism. And by the way, anything I denote as a "moral" issue is beyond debate other than by the uncaring forces of greed. His is a moralist's version of the intellectual vanity once ascribed to Oxford's Benjamin Jowett:

My name is Jowett

Of Balliol College;

If I don't know it,

It is not knowledge.

Many Iowans think it would be wise to nominate a candidate who, when the Republicans were asked during a debate to raise their hands if they do not believe in evolution, raised his. But, then, Huckabee believes America can be energy-independent in 10 years, so he has peculiar views about more than paleontology.

Huckabee combines pure moralism with incoherent populism: He wants Washington to impose a nationwide ban on smoking in public, show more solicitude for Americans of modest means and impose more protectionism, thereby raising the cost of living for Americans of modest means.

Although Huckabee is considered affable, two subliminal but clear enough premises of his Iowa attack on Mitt Romney are unpleasant: The almost 6 million American Mormons who consider themselves Christians are mistaken about that. And -- 55 million non-Christian Americans should take note -- America must have a Christian president.

Another pious populist who was annoyed by Darwin -- William Jennings Bryan -- argued that William Howard Taft, his opponent in the 1908 presidential election, was unfit to be president because he was a Unitarian, a persuasion sometimes defined as the belief that there is at most one God. The electorate chose to run the risk of entrusting the presidency to someone skeptical about the doctrine of the Trinity.

If Huckabee succeeds in derailing Romney's campaign by raising a religious test for presidential eligibility, that will be clarifying: In one particular, America was more enlightened a century ago.