Watching Dana in New York this week, as she linked up with the powerful institutions of the Catholic Church, I was struck by the historical irony of it all. Sitting there in the Waldorf-Astoria with a cardinal, seven bishops, and dozens of priests, nuns and prominent lay Catholics, she presented an image of seamless unity between religion and politics, between church and state. Her presence embodied certain assumptions - that to be Irish was to be Catholic, that Catholicism could be identified with very specific political positions, that churches were political organisations with an international agenda.
Did anyone there, I wondered, remember the history of the Catholic Church in America? Did anyone recall a time when one of the great demands of New York Catholic leaders was for pluralism and tolerance, for keeping religion out of politics, for a clear divide between church and state?
Back then, in the 19th and early 20th centuries, the boot was on the other foot, and Catholic immigrants in the United States faced prejudice and exclusion. They were a relatively weak and insecure minority, strangers in a Protestant land, prey to the prejudices of the Know Nothings and the Ku Klux Klan. Anti-Catholic bigotry made it impossible for a Catholic to win a national election - neither of the major parties had a Catholic candidate for presidency until Al Smith in the 1920s, and he was roundly defeated.
Back then, Catholic cardinals and bishops were often leading proponents of what we might now call secularism - the idea that democracy was best served by keeping religion out of election campaigns. When the Establishment was Protestant and its weight was being felt by Catholics, the separation of church and state was, for the Catholics, an eminently attractive idea. Some of the best, most cogent and most passionate elaborations of the idea of pluralist, open democracy came from leading Catholic churchmen, most of them of Irish origin.
Maybe it's easy to forget that history in the Grand Ballroom of the Waldorf-Astoria when the church leaders have gathered wealthy, powerful and aggressively militant members of the faithful around them. It is a sad but inescapable fact that the demand for openness and respect for diversity tends to be heard much more loudly among the weak than among the strong. How you feel about the need to separate religion and politics tends to depend on whether your particular brand of religion has a lot or a little political power.
When the Puritan or dissenting tradition was a despised and persecuted minority, it produced the greatest defences of free conscience. When it had its own states, in Geneva or parts of the early American colonies, it proved to be as repressive as any other. Oliver Cromwell, who produced the passionate plea for humility when his back was to the wall - "I beseech you in the bowels of Christ, think it possible you may be wrong" - was not so humble himself when it came to slaughtering Papists.
Jews, who forged a culture of enlightened compassion and tolerance out of their long history of persecution, have struggled to maintain it against the temptations of power in Israel. The Muslim attitude to the State in Ireland, where Islam is a minority religion, tends to be rather different to that in Iran. And of course this kind of double standard is not the preserve of religions. Political radicals who resent repression when they are out of power often end up repressing others when they get power themselves.
History would be a lot more pleasant to contemplate if religions and ideologies could remember it. The one common experience that all of them have is that of being, at some time or other, and in some place or other, on the receiving end of prejudice from a self-confident and hostile majority. Almost all of them have been told, in some context, "Look, this is our country, these are our values, we are the majority, you are the minority. The state must be founded on our rules, and if you don't like it then get out." And almost all of them have, in some other context, said the same words to someone else.
How quickly it is forgotten that the separation of church and state, freedom of conscience and the idea that people should be, in the public realm, respected as equal citizens rather than graded as true believers and infidels, are themselves religious ideals. They were invented by deeply committed believers who had experienced life under states that treated them as second-class citizens because those beliefs did not conform to the official norm.
One of the last places on earth where this amnesia should ever take hold is the island of Ireland. Few places anywhere have experienced so intimately and so recently the way in which minorities and majorities are unstable terms. All you have to do is cross a line and, if you are either Protestant or Catholic, you move from one category to another, from insider to outsider, from a citizen whose ethos is reflected by the state to one who depends on secular pluralism to protect you from the potential power of an overbearing majority. We, of all people, should know that the fusing of religion and politics is like saying that it's okay to play cards with a marked deck. So long as you own the deck, you can be sure of winning, but as soon as you play with anyone else's you will lose every time.
In a sense, of course, Dana's open alliance of religion and politics, church and state, is a sign that we do know all of that, that Irish society is now irredeemably secular. She is the first explicitly religious candidate for the Presidency because she has to make more or less explicit what there used to be no need to say. Ideas are most powerful when they can operate as unspoken assumptions, and for most of its history the idea that the Republic was a Catholic state was precisely that. It didn't need to be argued for, didn't need political parties or newspapers or specific candidates to make it an issue. When all the parties were Catholic parties, who needed a Catholic party? Those days are gone, and silent assumptions don't work anymore.
Those who believe, as Dana does, that their God (interpreted by themselves) is an authority above and beyond democracy, must nevertheless submit themselves to democratic rules.
It would be nice to think that when the election is over and Dana's supporters find themselves in a small minority, they might reflect on what a good thing it is for them that majority rule is qualified by respect for minorities, that the State is not just an embodiment of the values of the biggest group within it.
But, as the mixture of politics and religion at the Waldorf-Astoria this week so poignantly suggested, the righteous are not very good at remembering what it feels like to be on the outside.
Fintan O'Toole is temporarily based in New York