Defending Marriage?

One thing that's odd about the anti-gay-marriage discourse is that it's so often phrased as a "defense of marriage," as in the Defense of Marriage Act, which bans any Federal government recognition of same-sex marriage. Why "defense of marriage"?

Granted, a title like the Guys Kissing Is Gross Act would lack a certain gravitas. But are people really lying awake at worrying about the state of marriage? I decided to look into what effect gay marriage was having on divorce rates.

Unfortunately, the Census Bureau's 2012 Statistical Abstract only has data up to 2009, and at the beginning of 2009 only Massachusetts and Connecticut had same-sex marriage. But it's still interesting to look at the pattern that emerges. States that currently have same-sex marriage are shown below in italics.

Divorces per 1000 people, 2009
Nevada    
6.7
Arkansas       
5.7
West Virginia  
5.2
Wyoming        
5.2
Idaho              
5.0
Oklahoma      
4.9
...........
New Hampshire 
3.7
............
Vermont          
3.5
United States
3.4
............
Connecticut        
3.1
District of Columbia
2.6
New York
2.6
Illinois
2.5
Iowa
2.4
Massachusetts
2.2

Of the six states that had the lowest divorce rates in 2009, five now have gay marriage. Of the six states with the highest divorce rates, four now have constitutional prohibitions of gay marriage (West Virginia and Wyoming have statutory prohibitions).

What are we to make of this? Beats me, but maybe people in states where marriage is weakest are most concerned about defending it. If so, I doubt they're following an effective strategy.