Only the General Conference speaks for The United Methodist Church. When the lay and clergy delegates to General Conference approve a statement, it is published in the Book of Discipline and/or the Book of Resolutions. These words come from the people of The United Methodist Church.
http://www.umc.org/site/apps/nlnet/content3.aspx?c=lwL4KnN1LtH&b=4746363&ct=3169111
From The Book of Discipline of The United Methodist Church - 2012.
http://www.umc.org/site/apps/nlnet/content.aspx?c=lwL4KnN1LtH&b=5066287&content_id={1F927523-A422-4005-BA60-517220DB6D1E}¬oc=1
161 B) Marriage—We affirm the sanctity of the marriage covenant that is expressed in love, mutual support, personal commitment, and shared fidelity between a man and a woman. We believe that God’s blessing rests upon such marriage, whether or not there are children of the union. We reject social norms that assume different standards for women than for men in marriage. We support laws in civil society that define marriage as the union of one man and one woman.
Get any local UMW to preach that at any sermon. It'll never happen. Never.
For one thing, they're afraid of the 501C3 prohibition of preaching "politics" from the pulpit.