Newt Gingrich said on Friday that gay marriage was just a temporary aberration.

He couldn't be more wrong.

I believe that marriage is between a man and woman, Gingrich, the former speaker of the House and a Republican presidential candidate, told voters at a campaign stop in Iowa. It has been for all of recorded history, and I think this is a temporary aberration that will dissipate. I think that it just fundamentally goes against everything we know.

Of all the criticisms of gay marriage, that has to be among the most ridiculous, because since when has it's always been that way been a legitimate argument? Need I mention slavery? Or how about only white, male property owners being able to vote?

Unfortunately, Gingrich's remark was not at all unusual. Two weeks ago, another candidate, Minnesota Rep. Michele Bachmann, said much the same thing in an interview with Jay Leno: The family is foundational, and marriage between a man and a woman has been what the law has been for years and years.

That is fundamentally absurd. Lots of injustices were always that way -- until they weren't anymore.

Today, it seems that it was inevitable that the Jim Crow laws were repealed, interracial marriage legalized, women granted suffrage -- but when those fights were going on, those outcomes didn't seem inevitable at all. Today, it seems like there's a real possibility that gay marriage will stay illegal forever -- but it won't.

Martin Luther King Jr. liked to quote the abolitionist Theodore Parker: The arc of the moral universe is long, but it bends toward justice. The key word is long, but it is true: History moves toward more freedom and more rights for current and future generations compared with previous ones. It moves painfully slowly -- two steps forward, one step back and sometimes not even that -- but over time, rights are broadened, not narrowed.

Gay marriage is not an aberration. Eventually, it will be the status quo -- maybe years from now, maybe decades from now, but it will happen as surely as the United States extended voting rights from property owners to non-property owners, from whites to blacks, from men to women.

Fifty years from now, history books will look at Gingrich, Bachmann and their closed-minded ilk the same way today's history books look at supporters of the Jim Crow laws, of anti-miscegenation laws, of voting restrictions and of slavery: as shameful aberrations in the arc of American history.

Increased rights are inevitably controversial at first -- but in the end, rights, not bigotry, win every time.