It is much easier to dislike an ethnic or religious minority in the abstract than it is in reality, which is why so many people are determined to remain comfortably within their bubbles. This same principle applies to dislike or mistrust of gays, which is why Senator Rob Portman of Ohio last week became the first Republican senator to express support for gay marriage.

In an op-ed column in Friday's Columbus Dispatch, Senator Portman wrote that "I have come to believe that if two people are prepared to make a lifetime commitment to love and care for each other in good times and in bad, the government shouldn't deny them the opportunity to get married." The senator linked his transformation to learning that one of his sons is gay. A White House budget chief under President George W. Bush, Mr. Portman said he discussed his change in position on gay marriage with former vice president and arch-conservative Dick Cheney, whose daughter is a lesbian. Mr. Cheney announced his embrace of gay marriage four years ago.

It is unfortunate that it takes real-world experiences to convince public officials that gays have rights and pose no threat to the institution of marriage, but it works the same way for private citizens who are anti-homosexual until they find that a son, daughter, niece or nephew is gay. Senator Portman's above statement may be as eloquent an argument for gay marriage as can be written, and it also stands as an eloquent argument against the federal Defense of Marriage Act, whose constitutionality is being challenged in court, with Massachusetts Attorney General Martha Coakley helping to lead the attack.

The Republican Party's stance on gay marriage is hugely contradictory, as the party that trumpets the need for "small government" when it comes to economic matters also advocates government interference in the lives of Americans when it comes to the constitutional rights of a minority. Senator Portman finally came to see that contradiction, and as others do the same, opposition to gay marriage and other gay rights will continue to evaporate.