Support for same-sex marriage is now in the Democratic Party preliminary platform. Once approved by the full platform committee and voted on at the convention, same-sex marriage will have the party's formal support.

But as Democrats institutionalize their support for same sex-marriage, their relationship with the party's most loyal constituency, black Americans, becomes increasingly uneasy.

A new survey just released by the Pew Forum on Religion & Public Life shows 65 percent of Democrats support same-sex marriage compared to just 40 percent of blacks.

A group of 3,700-plus black pastors, the Coalition of African-American Pastors, under the leadership of the Rev. William Owens, has moved to formally oppose the Democratic Party and President Barack Obama on this issue.

The group is spearheading a "Mandate for Marriage" campaign to gather 100,000 signatures on a petition declaring support for traditional marriage. The petition also calls for Obama "to repudiate his assertion that gay marriage is a civil right."

These black pastors are not in the business of politics, nor are they policy wonks. They are driven by commitment to biblical truths and the direct challenge to and rejection of these truths by social acceptance of homosexual behavior and same-sex marriage.

They don't see biblical truths as academic points divorced from the practical realities of life. They see them as the rules that sustain life. And they see the crises spreading in their communities and in our nation as acceptance of these truths falling by the wayside.

HIV/AIDS is devastating black America. Reading the grim statistics from the Centers for Disease Control and Prevention makes clear that this plague is driven, first and foremost, by homosexual behavior.

According to the CDC: "In 2009, African-Americans comprised 14 percent of the U.S. population but accounted for 44 percent of all new HIV infections. ... Black men accounted for 70 percent of the estimated new HIV infections among all blacks. ... Black men who have sex with men represented an estimated 73 percent of new inflections among black men. ..."

Research abounds showing the importance of intact traditional family life in the academic success of children and of overall economic health.

In recent testimony before the Senate Finance Committee, Ron Haskins of the Brookings Institution noted that individuals who follow three rules -- complete at least high school, work full time and wait until age 21 and get married before having a baby -- have a 2 percent chance of winding up in poverty and a 72 percent chance of being in the middle class.

Since the 1960s, American family life in general has deteriorated with the departure from traditional values and the concomitant growth in government and the welfare state.

But deterioration of black family life has been the most pronounced.

In 2008, according to a Pew Research Center report, 32 percent of black adults were married, compared to 61 percent in 1960.

These black pastors understand that collapse of family, out-of-wedlock births, single-parent households, promiscuity, drugs and crime are the crises undermining black physical and economic health today. And they understand that a society that validates alternative lifestyles that undermine life-sustaining biblical truths is a society that will inevitably promote and advance this deadly behavior.

They understand that the weakest communities -- their own communities -- are the most vulnerable.

This Coalition of African-American pastors is showing, very much in the spirit of the civil rights movement, that the political choices facing blacks are not limited to deciding which political train to get on. They are jumping up front to influence where the train is going.

It's high time for blacks to serve up some black tea to the Democratic Party, as the Tea Partiers are doing with Republicans, and move to change the values and direction of the party they have loyally supported but that no longer represents their interests.