"It is exceedingly desirable that all parts of this great Confederacy shall be … in harmony. … Even though the [other side] will not so much as listen to us, let us calmly consider their demands …

"What will satisfy them? Simply this: We must … cease to call [the practice over which we differ] wrong, and join them in calling it right. And this must be done thoroughly — done in acts as well as in words. … The whole atmosphere must be disinfected from all taint of opposition …"

No one has ever equaled Abraham Lincoln in describing the crisis of mutual intolerance that grips a society divided over a basic moral issue. In the passage above from his famed Cooper Union Address, Lincoln explained why each side in a pitched moral standoff can settle for nothing short of unconditional surrender from the other.

"Holding, as they do, that slavery is morally right, and socially elevating, " he continued, "they cannot cease to demand a full national recognition of it. … Nor can we justifiably withhold this, on any ground save our conviction that slavery is wrong. … Their thinking it right, and our thinking it wrong, is the precise fact upon which depends the whole controversy …"

It was useless, Lincoln added, to search for "middle ground" in a dispute over what was right and what was wrong — it was "vain as the search for a man who should be neither a living man nor a dead man …"

It may be a hazardous stretch to compare any controversy to the slavery conflict. But the pummeling Indiana has suffered over its new "religious freedom" law — under the spotlight of this weekend's Final Four in Indianapolis — reveals anew the absolutist, "house divided" spirit that has long possessed both sides in America's battle over same-sex marriage.

For years, it was opponents of gay marriage who demanded total victory. They pushed through a federal Defense of Marriage Act to deny federal benefits to same-sex couples even if individual states legalized their marriages, while empowering other states to also refuse recognition to those unions. They added same-sex marriage bans to more than 30 state constitutions, lest mere statutes outlawing gay marriage were inadequate to deter progressive courts disposed to expand gay rights.

Of course, to the extent that conservative culture warriors justified such tactics by arguing that marriage traditionalists would quickly lose everything if they gave an inch — well, events have proved they were right to fear that resistance to same-sex marriage was fragile.

Nowhere was the reversal of fortune more swift and decisive than in Minnesota, where a Republican Legislature confidently placed a constitutional gay-marriage ban on the ballot in 2012, only to see it fail at the polls, emboldening a DFL Legislature to legalize same-sex marriage outright the following year.

The gusty winds of change have blown nationwide. Through a combination of legislation, referendums and — most commonly — court decisions, same-sex marriage has been made legal in 37 states in just the past few years, as opinion polls have shown a stunningly rapid change of heart toward support of a new definition of marriage.

The fiery backlash against Indiana is just the latest evidence that, in their apparent victory, the champions of marriage equality intend to give no quarter — to tolerate little social or legal space where people who continue to believe that same-sex marriage is wrong might at least not have to behave as if they believe it to be right. It almost seems as if the whole national atmosphere must be "disinfected from all taint of opposition."

At the risk of spreading quarantined sentiments, I have to confess to some sympathy for people who are on what looks like the losing side of this culture-war battle. The issue carries no religious imperative for me, but I've wrestled with worries about possible unintended effects of redefining a basic social institution in this way.

Yet Minnesota's lengthy public debate of the issue, and its two-step democratic process to effect legalization, has confirmed that here that redefinition is the community's considered choice.

It hasn't worked that way in Indiana, one of 26 states where marriage customs have been transformed by courts (often, as in Indiana, federal courts) overturning traditional laws under what is surely debatable constitutional reasoning.

It's frankly hard to take seriously the denial from Indiana officials like Gov. Mike Pence that the state's decision this spring to finally enact its own version of a "Religious Freedom Restoration Act" (RFRA) has a lot to do with the federal court order legalizing gay marriage in Indiana just last fall. But it's true that Indiana's law is almost identical to a long-standing federal statute and derivative laws in dozens of other states. Minnesota court rulings suggest that our state Constitution provides if anything even stronger protection for individual freedom of conscience.

It's unclear whether such legal provisions might permit, say, some religious business owners to refuse service to same-sex weddings (rather as the federal RFRA was held last year to allow religious employers to avoid providing contraceptive insurance coverage). But the possibility stokes passions on both sides.

My vantage point as commentary editor during Minnesota's long debate over same-sex marriage helped me better understand this dispute's bitterness. In hundreds of essays arguing both sides of the issue, it became clear that advocates of same-sex marriage and its opponents both have practical, pragmatic reasons for their views. But it became even plainer that at bottom what both groups most deeply desire is their community's respect and affirmation.

Weary of dwelling in a shadow land of, at best, grudging toleration, gay and lesbian Minnesotans wanted their lives and loves acknowledged and honored by the society they live in. But religious conservatives felt that if society affirms same-sex marriage, it is unavoidably repudiating the beliefs of those whose faith tells them it is wrong.

The protections of religious-freedom laws like Indiana's may seem to some of these new cultural exiles like little more than shadow lands of grudging toleration. And even those are now begrudged them.

A genuine truce seems improbable on an issue like this — where two communities of belief long for their culture's blessing, and only one can have it. But the inevitable wounds might heal more effectively over time if the dispute could be resolved across the country following the Minnesota model of democratic debate and decision.

Instead, sadly, we seem on track to see the nation's judges sweep political deliberation aside and risk giving America what it really doesn't need — another Roe vs. Wade, a culture-transforming court decree that remains a cause and symbol of political and social estrangement four decades after it was handed down.

D.J. Tice is at Doug.Tice@startribune.com.