DETROIT — The national Democratic Party’s platform committee endorsed gay marriage Saturday for the first time and called for the repeal of a federal law that recognizes marriage as between a man and a woman.

The committee, meeting in downtown Detroit, let stand the work of a separate group that drafted the platform two weeks ago in Minneapolis. The platform is a broad statement of the party’s priorities on the economy, social issues and national defense and next goes to the national convention in North Carolina in September.

Scott Dibble, a committee member and a state senator from Minnesota, said support for gay marriage can attract new voters.

“Young people are looking for a political home right now. This has become a defining moral question of our time,” said Dibble, who is gay.

The platform says Democrats support “marriage equality” and the “movement to secure equal treatment under law for same-sex couples.”

“We also support the freedom of churches and religious entities to decide how to administer marriage as a religious sacrament without government interference,” the platform says.

In May, President Obama said he personally supported gay marriage.

“This certainly been a journey for many people in this country, a journey for our president,” Dibble told fellow committee members from across the country.

The platform also calls for repeal of the Defense of Marriage Act, a 1996 law signed by Democratic President Clinton that recognizes marriage as between a man and woman. Some federal courts have struck it down as unconstitutional.

Newark, N.J., Mayor Cory Booker, co-chairman of the platform committee, said there are “profound indignities” heaped on people who can’t marry someone of the same sex.

“At the end of the day it’ll maybe repel some and attract others to be more engaged,” Booker told reporters, referring to the platform plank. “This campaign is not going to turn on gay marriage. This campaign is going to turn on who has the best ideas for the economy.”The platform is a broad statement of the party’s priorities on the economy, social issues and national defense and next goes to the national convention in North Carolina in September.