But Tegeder and others say the archbishop is walking a fine line, potentially imperiling the church's neutrality, if it is using financing from political groups.
Nienstedt, who says he does not know how much the DVD campaign cost or who donated the funds, insists the DVD is not political but part of an ongoing effort to educate Minnesota Catholics about marriage.
"We, and I'm particularly, are very scrupulous about not endorsing any candidate of any party," Nienstedt said in an interview with Minnesota Public Radio last week. "That's not our position. That's not our right.
"We need to bring this to the people," he said of the constitutional amendment, "rather than have it decided by the judiciary or by the legislature. ... We need to let the people say what the reality of marriage is going to be. I don't see that as that big of a political statement."
In recent years, religious groups, including the Catholic Church, have led and supported campaigns against same-sex marriage in several states, most prominently in California, where voters approved a ballot measure known as Proposition 8, banning the unions in 2008.
Thirty-one states have constitutional provisions defining marriage as between one man and one woman. Five states -- Massachusetts, Iowa, Connecticut, Vermont and New Hampshire -- and the District of Columbia perform same-sex marriages.
The Emmer campaign became a flashpoint over same-sex marriage earlier this year when Target Corp. and other prominent Minnesota-based companies donated money to a political advocacy group running ads supporting Emmer. Gay and lesbian rights groups, employees and some customers protested the donation because of Emmer's stance on same-sex marriage.