It just occurred to me that gay marriage is like Obamacare.
If you ask people if they like major components of Obamacare, like letting children stay on their parents’ health insurance until they are 26 or making sure that those with preexisting conditions get insurance, people say yes. But when you ask people if they like Obamacare, a majority says no.
Similarly, if you ask people whether gay couples should have particular rights that spouses normally have, such as hospital visitation, they say yes. But when you ask people if they support gay marriage, many more say no than on the individual benefits.
In both cases, the whole is greater than the sum of its parts, and in a way that hurts President Obama and helps Mitt.
Embattled Farmers 
What you say is true but it should be added that it may be rational for some people to dislike Obamacare in all of its applications while it is wholly irrational to oppose gay marriage at all.
For some people it is very strongly scripture-based. It is not irrational, it goes against everything we’ve accepted for thousands of years of human history, it’s in our collective unconscious.