Homogamy tipping point: breaking the curve edition

Before the Supreme Court added the behemoth California to the list, I said homogamous marriage was spreading exponentially, in a bona fide tipping-point shape  (not to be confused with the bogus tipping points all over the news). With today’s update (adding Utah and four other states), the trend is breaking the exponential curve.

If you fit an exponential curve to the dots, it only gets up to 20% for 2013.

(Note this chart has imitators out there, but I haven’t seen any that calculates the population percentage using the U.S. population as it changed from year to year. Note also it hardly matters.)

Note: On the term homogamy.

 

Homogamy tipping point update: between elections edition

After the last election I described the trend toward legal homogamy as taking a tipping point shape. Not a media-hype tipping point that’s really just a milestone or watershed (like the arbitrary 50%), but a bona fide straw-that-breaks-the camel’s-back shape – that is, an exponential trend.

The between-election update shows us continuing on that trend, with Rhode Island and now Delaware falling on the line. Here I’ve plotted the percent of the population living under a post-homogamy state regime, and the number of states (including DC):

Even assuming they don’t legalize it nationally, if the Supreme Court lets California’s homogamy law stand after all this graph will go through the proverbial roof.

On the other hand, of course, the future is not yet determined. We won’t know till it happens what happened. In that I must agree with the Family Research Council, Heritage Foundation and National Organization for Marriage, who write in a recent pamphlet:

Q: Isn’t same-sex marriage inevitable?
A: No.

(I disagree with the rest of the pamphlet.)

Have we passed the homogamy tipping point?

A tipping point is when a small step along a continuous path suddenly makes a big, irreversible difference in some outcome. Here’s one illustration (which I got here):

The little bits of action have been having a little impact, until suddenly one more little bit of action creates a big impact — the straw breaks the camels back. In real life these moments are very hard to predict, and even in retrospect it’s not so clear what did it.

Legal homogamous marriage is spreading in the U.S. (and the world). The restriction on marriage increasingly looks like a crude, irrational violation of equal rights. A growing share of the public sees no reason to object to gay and lesbian marriage.

This doesn’t follow a tipping-point pattern, at least not yet. But here is a case where 50% is potentially a tipping point rather than a mere milestone or watershed. That is because of 50%+1 winner-take all voting. And that’s why this week’s successful ballot measures in three states in favor of legal homogamous marriage– Maine, Maryland and Washington — are so important.

But the tipping point actually may have preceded them, when marriage rights broke out of New England, in Washington, D.C. in 2010, by a city council vote. (Iowa went earlier by court order.)

When New York followed DC by legislative action in 2011, the percentage of the population in marriage-equality states more than doubled, from 5% to 11%. Even without the judicial branch, which will do something in the next year or so, the trajectory here is steeply upward.

In a truly Rovian moment of prognostication, Brian Brown from the National Organization for Marriage gave this analysis earlier this year:

Proponents of same-sex marriage have created a myth of inevitability, and folks in the polling world have used language that has often helped them… The only poll that counts is the voters, and if you look at that, we’ve won every single one. If you look at trend lines, the trend lines are in our direction.

And that makes sense (that is, the opposite of what Brown said): if we’ve shifted to a majority, or close to it, nationally, then plenty of states and local areas are well beyond 50%, and that’s enough for ballot measures where they are permitted.

As a result of social movement action, legal challenges, changing attitudes, and cohort replacement, marriage equality appears to be spreading, like a forest fire or disease epidemic — only better.