But progressives who attack those who disagree with them about marriage as “bigots” should not be able to get away with this smear while simultaneously giving liberal politicians such as Barack Obama a pass. They need to give us an answer: If opposing the redefinition of marriage is bigotry, then what is Barack Obama, a bigot or a liar?

It has become a matter of orthodoxy among progressives that those who believe that marriage is properly defined as the union of one man and one woman are guilty of bigotry.

There is a problem, however: Barack Obama has assured voters that he believes marriage to be the union of one man and one woman — not two men, two women, or some combination of more than two people. As Donald Trump rather pointedly noted after the Miss U.S.A. pageant, President Obama’s position on the definition of marriage is identical to the position stated by California beauty queen Carrie Prejean.

So what do progressives think? Has the president embraced bigotry? Or has he lied to the American people about his position on what marriage is and how it should be defined?

On either side’s account, the dispute over the nature and meaning of marriage is profoundly important. Those who seek to redefine marriage to include same-sex or even polyamorous relationships believe that the historical definition of marriage as a male-female union denies people who incline toward other forms of sexual partnership equality and fundamental rights. Those who defend the historical definition — I am one of them — believe that redefining marriage will further erode public morality and weaken the already battered institution of marriage.

So if the president is lying, he is lying about something that really matters. It is no innocent fib (like Robert Gibbs’s fib that the president did not bow to the Saudi king).