It is easy to find examples of people who wound up on the wrong side of history: Strom Thurmond was so far on the wrong side of history that he ended up bringing down others — not that Trent Lott didn’t deserve it — with him. It’s not so easy to avoid getting there. The problem isn’t the impossibility of prophesying the political future — pre-emptive political correctness? — it’s a distaste for assimilating the lessons of the past. Politicians, generals and defense secretaries who don’t learn from history tend to become its whipping boys. The danger of wagering on history is that you can lose your shirt.

Last week, San Francisco Mayor Gavin Newsom ordered that the city must not only recognize gay marriages, but perform them. Newsom was immediately compared by the Wall Street Journal to Alabama Judge Roy “Ten Commandments” Moore. Is SF just being SF, or is Newsom, a savvy and extremely ambitious politician, placing a bet on history?

Probably both. The issue of gay rights in San Francisco is like ethanol in Iowa, but Newsom’s intuition tells him he will be in a column with Rosa Parks, not Strom Thurmond, on history’s balance sheet; and he wants to get in while the getting is good. If he didn’t make the wager that gay marriage will one day be common practice, some other politician would.

Newsom is no crusader. He’s a moderate. He may argue that gay marriage is in the equal-rights spirit of the constitution, but he is also perfectly aware that the republicanism that is practiced in America and written into our constitution consists of both democratic values (majoritarian rule) and classical liberal values (protection of individual and minority rights), and that only politics — to the great dismay of all those who condemn “judicial activism” — determines which we emphasize in reading the constitution in any given case. But Newsom also knows that from a purely historical standpoint, the history of emancipation in America for blacks, women, Native Americans — is the history of majoritarian institutions like slavery and Jim Crow transforming into liberal ones, but always one or two or several generations too late. Newsom may not get credit for doing it on time, but he can still get credit for doing it first.

Gay rights are frequently called a “wedge issue,” an issue used to force socially conservative voters who may have doubts about Bush’s tax cuts or foreign policy back into the Republican fold. David Brooks of The New York Times and others have argued that gay rights is not a wedge issue at all, but a critical moral issue of the same stature as preserving social security and Medicare.

Only time will tell if gay rights becomes a “wedge issue” in this year’s presidential campaign; it all depends on how the issue is used. George Bush may care deeply about the sanctity of marriage, and Karl Rove probably doesn’t. But the wedge issue question doesn’t really matter. Brooks argues that as long as we have a sober debate, rather than a partisan shouting-match, we vindicate ourselves. While it would be preferable to have a serious debate, no amount of solemn deliberation can erase the fact that there are rights and wrongs that only history can decide.

The real question is whether America will ever learn from its history and grant equal rights to another minority group sooner rather than later. San Francisco might be wrong. Perhaps gay marriage actually will weaken marriage; perhaps the most frivolous heterosexual marriage — Andrew Sullivan and others have mentioned Britney Spears’ recent shotgun marriage in Vegas as spin control for the conservative “sanctity of marriage” rhetoric — is infinitely more valid than the most sincere gay union. But if gay marriage is wrong, it will not be because a majority thinks it’s wrong. Too much has been made of the “genie” of democracy in recent years; maybe it prevents war, but it doesn’t prevent getting body-slammed by history. The only reason American can be called a democracy at all is that civil rights are extended after many long, hot summers and many struggles against majoritarian intransigence.

That is perhaps a lesson aimed at John Kerry, who has scrupulously avoided supporting anything beyond civil unions because of popular disfavor – even his own state’s supreme court’s ruling that civil unions are just another version of “separate but equal.”

There’s a message for the right, too — after all, learning from history is a bipartisan project. The message for the right is that religious belief is no better protection against history than democracy. Religion has been used to justify slavery, terrorism and forced conversion. The Bible condones slavery at least as clearly as clearly as it condemns sodomy. Future generations will not care why those on the wrong side of history believed what they believed or how fervently they believed it.

While most Americans’ attitudes towards gay marriage continue to be negative, some polls suggest their expectations about gay marriage don’t reflect their preferences. Instapundit blogger Glenn Reynolds has polled his law school classes at the University of Tennessee and discovered that most students expect gay marriage to be legal in ten years, irrespective of their political views. Will that be because of activist courts (as an Instapundit letter-writer suggests), or because someday soon Americans will finally internalize the idea of full equality, not to mention the lessons of history?

The point of all this is to say: choose your wedge issues well, because hell hath no fury like the judgments of history.