Matthew Franck points out that since Obama says his faith inspired him to change his views on marriage, then all people of faith are not "imposing their religion" when they act to protect marriage:

"...Well, one of the endlessly repeated arguments of the advocates for this revolution in the meaning of marriage is that the defenders of the only meaning of marriage ever known in human history (that it unites men and women to form families) are “imposing their religion” on people who disagree with them. This is supposedly un-American, unjust, unconstitutional, unconscionable—un-you-name-it.

As I have explained elsewhere, this criticism is shot through with errors about the Constitution’s requirements, logical fallacies about the relation of morality and religion and of faith and reason, and general thuggishness. That has not prevented it from being popular with same-sex marriage advocates, and even some judges in Iowa and California.

Here I will content myself with observing that every one of these wrongheaded criticisms is exactly on point as a criticism of President Obama and all other supporters of same-sex marriage who rely in any way on their faith, as they understand it, to justify their support. If the people of California can be faulted for “imposing their religion” on their fellow citizens by passing Proposition 8, then it is equally true that President Obama is “imposing his religion” on his fellow Americans when he says, as he did last week, that laws preventing same-sex marriage are unjust to gay couples desiring to get married. If he is not imposing his religion on anyone, neither is anyone else. -- The Washington Post's Guest Voices Blog