In the less enlightened days of America's past, it was illegal in some places for blacks to marry whites, for women to vote and for people of color to occupy the same public spaces as whites.

The laws were racist, sexist and discriminatory -- and the nation came to understand the human toll. Unfortunately, we're still struggling to get it right when it comes to same-sex marriage.

A proposal sailing through the Legislature would only make matters worse here in Minnesota. Committees of both the House and Senate have passed measures that call for a statewide vote on a constitutional amendment to ban same-sex marriage.

Passing a misguided gay marriage ban by referendum would cement inequity into the state Constitution. Requiring a majority vote to affirm minority rights is inherently discriminatory.

Many of our nation's civil, human and women's rights laws might never have passed if they were put to a vote. Instead, those advances usually came through legislative and court decisions that valued human rights more than special-interest politics.

Minnesota already has the curiously named Defense of Marriage Act (DOMA), which prohibits same-sex couples from marrying. That's the status quo in many other states as well, although there's no evidence that heterosexual marriages need to be "defended" from gay and lesbian unions.

Loving relationships between two men or two women have absolutely no impact on other matrimonial commitments. Nor do they pose any threat to the institution of marriage or family life, as the amendment backers claim.

And yet opponents of marriage equity say a constitutional amendment is a necessary backstop that would prevent the courts from overturning existing law.

In reality, enshrining this form of bigotry in the state's premier governing document would be a step backward. Rather than reinforce an already discriminatory law, core values of equity and fairness should compel Minnesotans to repeal DOMA and extend marriage equity to all.

We understand that emotions on this issue run deep. The debate hits numerous religious and moral hot buttons, for secular and sacred reasons. Concurrent with their beliefs, religious organizations may indeed decide who they will marry with their blessings.

However, government is not and should not be a church, synagogue or mosque. Marriage under the law is a next-of-kin, legal arrangement that includes important property, benefits, child custody and health care rights. Those legal rights should be available to all couples.

Creating an even more hostile environment for gay marriage would also have a negative impact on business and the economy -- as Target Corp. painfully learned last year. After the Minnesota-based company gave $150,000 to a group supporting Republican gubernatorial candidate and gay-marriage opponent Tom Emmer, staff and customers called for boycotts.

Eventually the company apologized, restated its commitment to gay rights and changed its political contributions policy.

It's likely Republicans see the window of opportunity closing on their efforts to pass antigay legislation. Banning gay marriage through the Constitution would put Minnesota at odds with a growing tide of tolerance and acceptance.

A Pew Research Center poll late last year showed that 42 percent of Americans supported allowing gays to marry -- up from 37 percent the year before -- and for the first time in 15 years of Pew's polling, fewer than half were opposed.

The trend is clear: Younger Americans embrace a more inclusive view of human rights.

Despite strong arguments against it, the marriage ban amendment has a good chance of being on the ballot next year. If that happens, Minnesotans should consider the state's past discriminatory blunders and do all they can to vote it down.

To offer an opinion considered for publication as a letter to the editor, please fill out this form. Follow us on Twitter @StribOpinion and Facebook at