MINNEAPOLIS — The campaign working to defeat the constitutional amendment to ban gay marriage is holding a major rally at the University off its get-out-the-vote efforts.

The Minnesotans United for All Families rally is at 6 p.m. in front of Northrop Auditorium. Minnesota’s two Democratic U.S. senators, Amy Klobuchar and Al Franken, are scheduled to participate as is Minnesota Vikings punter Chris Kluwe, a major critic of the amendment.

Organizers are expecting up to 1,000 people at the campus rally. Minnesotans United is focusing turnout efforts on college students, who polls say are strongly in favor of gay marriage rights.

Backers of the amendment say it’s needed to make sure that voters, not elected officials or judges, can decide the definition of marriage in the future.