When an otherwise reasonable man starts to make no sense at all, it is standard practice in emergency rooms to test for West Nile virus or encephalitis or a bad reaction to one drug or another. If, however, that man is a politician, then no test is needed. Delirium is caused by running for president as a moderate Republican. No one can do that and keep his sanity.

To back up my medical diagnosis I offer the recent statements of George Pataki, governor of New York, and Mitt Romney, governor of Massachusetts. Both men are coming to the conclusion that their country desperately needs them, and their thoughts have turned to a White House occupancy, sometime around January 2009. Pataki has announced that he will not seek a fourth term, he has recently been to Iowa, and -- after an entire career spent as a pro-choice Republican -- he has said he will veto a bill that would have made the "morning-after" pill available without a prescription. He said he does not like making the drug available to minors, who, come to think of it, are precisely the ones most likely to need it. Go figure.

Similarly, Romney, too, is finding himself in a strange mood when it comes to abortion and similar matters close to the hearts of conservative Republicans. As he mulls a presidential run, he has been mulling abortion, too. He has discovered -- maybe in Iowa, where he, too, has been -- that his position has changed. He is no longer pro-choice, as he was during his 2002 gubernatorial race, when he issued a statement commendable for its brevity and common sense: "Women should be free to choose based on their own beliefs, not mine and not the government's." That position has now been amended to something even briefer: Women should not have the right to choose. In a Boston Globe op-ed piece, Romney says his views on abortion have "evolved and deepened."

Maybe so. And it is possible that Pataki, too, is absolutely sincere in his objections to the morning-after pill. But if that's the case, he should have made his objections clear when the bill was under consideration by the legislature and still amendable. His second thoughts, in any event, are somewhat specious. It's precisely underage girls who need the pill the most, since they are the most easily addled and pressured -- or so I have read. Whatever the case, the vast preponderance of expert opinion considers the pill safe, and it is routinely prescribed in emergency rooms, I am told by a physician with whom I checked. It's apparent that the main objection to the pill is religious or moral or cultural -- call it what you want. As far as some people are concerned, the pill is an abortion agent. As far as others are concerned, it encourages premarital sex. Taken together it is clear: The pill does not work in red states.

Pataki and Romney are not the only Republicans who have slipped on a banana peel while running after the far-right vote, which is crucial in the GOP presidential primaries. Bill Frist did so when, after viewing a videotape, he pronounced Terri Schiavo to be responsive to stimuli when, as we now know, she was in even worse shape than some had imagined. For an esteemed physician to make such a fool of himself in chasing the skirt of the religious right is an indication of how far things have gone. It has become clear that a viable Republican presidential candidate must oppose abortion, stem cell research, the morning-after pill, gay marriage and, for good measure, evolution. At the very least, you have to offer a good word for "intelligent design," as the president did just the other day in the single dopiest statement of his presidency.

These are positions that defy logic -- not each and every one of them but as a totality. Taken together, they require GOP presidential candidates to take a kind of loyalty oath to ignorance, to see virtually every issue through a religious prism. That won't bother some candidates, but it will bother moderates. As Pataki and Romney have done, these Republicans might think that they can, in the heat of the moment, say whatever is necessary to gain the nomination and afterward revert to who they really are. But to both the left and the right they seem only blatantly opportunistic. It's an image that will stick. In politics, unlike sex, there is no morning-after pill.