It’s hard to believe that Howard Dean and Dick Cheney agree on anything, but both the firebrand Democrat and the resolutely conservative vice president favor civil unions for same-sex couples.

I’ll let that sink in for a moment.

From two leaders as different as Bart Simpson and Lawrence Welk, this is a remarkable meeting of the minds. Dean became a hero of sorts in the gay-rights movement in 2000 when, as governor of Vermont, he signed the nation’s farthest-reaching civil union law. Cheney, no civil-rights flag-waver, said during the last presidential campaign that states should be left alone to regulate such things, a stand that combines his fierce libertarianism with a father’s tolerance. His lesbian daughter, after all, lives openly with her partner.

These political oddfellows may signal among Americans a growing acceptance — or at least a growing comfort level — with a formulation that sanctions civil unions but stops short of embracing gay marriage. It is a formulation that could help bring together the people, myself included, who are loath to redefine the tradition of marriage and yet reluctant to prevent two loving people from living together happily ever after.

This is why last week’s all-or-nothing ruling by Massachusetts’ high court is so disturbing.

In an unusually divided and acrimonious opinion, the justices slapped down the legislature’s attempt to broker a civil-union compromise, invoking the rhetoric of the civil-rights movement to remind that separate does not make equal, and asserting that only the actual word marriage can confer on gay couples the legitimacy and privilege they deserve.

It was as if a giant smoke bomb went off in statehouses across the land, sending lawmakers scurrying back to their offices to grab a musket and take up their newly hardened positions.

This may not have been a shot heard round the world, but the shocks certainly will rumble through the nation. The ruling emboldened those who wish to rewrite the Constitution — a document expressly limiting the reach of the federal government, a document that didn’t even mention God, voting or slavery — to define marriage as a union occurring only between one man and one woman. What would James Madison think?

But the Massachusetts justices also arrogantly dismissed those of us seeking common ground and the opportunity to reconcile centuries of tradition and teaching with contemporary notions of freedom and sexuality. Accepting gay marriage inexorably and radically redefines marriage, and some of us may not be ready to go quite that far, now, or maybe ever.

The civil-union compromise would grant public legitimacy to gay couples — the rights to visit the hospital and adopt a child and plan a funeral — while allowing faith communities the freedom to define marriage according to their beliefs and traditions. Yes, it is half a loaf. It is separate but equal.

It also would be a tremendous step forward for gay and lesbian couples. Just as important, it allows officials to weigh the interests and anxieties of their constituents and to work through the political process for answers that may vary from state to state, community to community.

America needs this conversation. For the 55 percent who believe it is a sin to engage in homosexual behavior, and the 42 percent who believe such behavior can be changed, there’s probably little to discuss. For the rest of us, who in the words of writer Andrew Sullivan believe that “homosexual orientation is a given of human nature,” questions abound.

Can a society that prizes equality privilege one type of union over another? Good question. But here’s another. If all unions are equal, if anything is acceptable, is nothing valued? Does gay marriage diminish the already weakened status of marriage, battered after years of no-fault divorce, increasing out-of-wedlock births, and a general disdain for commitment? Or will it infuse the institution with new proponents and role models?

I’m willing to bet that a great many Americans share my confusion. We who are not so defiantly sure of our position on this great moral issue must be encouraged to think and deliberate, not pushed into one corner or another.

In Merriam Webster’s unabridged dictionary, the word marriage is first defined as the legal union of a man and woman as husband and wife. A secondary meaning describes a play in pinochle, a combination of a king and queen of the same suit.

Please, let us take some time before we shuffle the cards completely.

Jane R. Eisner is a senior fellow at the University of Pennsylvania and a columnist for the Philadelphia Inquirer. Her e-mail address is jeisner@phillynews.com.