A few years back, the city of Cincinnati tried to reduce on-street litter by prohibiting the distribution of “commercial handbills” from sidewalk news racks. The city allowed the coin-operated news racks to remain, however, on the theory that people were more likely to discard free commercial shoppers than bought-and-paid-for newspapers.

The policy seemed sensible, but not sensible enough for the Supreme Court, which turned its attention to the commercial publishers’ First Amendment rights. The justices in 1993 ruled the policy unconstitutional on the ground that Cincinnati had failed to show a “reasonable fit” between its anti-litter goal and the selective enforcement scheme adopted to further the goal.

The decision illustrates in an unremarkable way the courts’ well-established role in critically examining the rationality of legislative or executive branch policies that affect constitutional rights. As important as the First Amendment is to our society, one might think that courts would be at least as rigorous in scrutinizing the basis of laws affecting more personal liberty interests, including the right to select a life partner.

Last month, however, the highest courts in two states — New York and Washington — were far less than rigorous in finding a “rational basis” for laws denying same-sex couples the right to marriage. The two blue-state rulings — which leave Massachusetts alone in recognizing marriage for same-sex couples — have forced gay rights supporters to reconsider litigation as a strategy for achieving marriage equality for gay men and lesbians.

The judicial setbacks for gay rights supporters reinforce a growing body of thought among liberals against using courts instead of legislative bodies to establish new civil rights and liberties. Jeffrey Rosen, a professor at George Washington University Law School and frequent legal commentator, provides the most extended recent version of this thesis in his new book, “The Most Democratic Branch: How the Courts Serve America.”

Rosen argues that courts can reliably safeguard individual rights only if they already are recognized for the most part by a “constitutional consensus” among Congress, the president and the public. In his view, Brown v. Board of Education survived because the public was ready to bury racial segregation. Roe v. Wade became a battleground because Americans were not — and still are not — ready to accept what opponents call “abortion on demand.”

Rosen cites the Massachusetts decision on gay marriage along with Roe as examples of “judicial unilateralism.” He calls instead for “judicial restraint,” which he depicts as a “venerable tradition” under siege from activists of the left and the right.

The New York and Washington decisions on gay marriage, however, represent restraint at the expense of reason. The two grounds that both courts cited as providing a rational basis for limiting marriage to opposite-sex couples fall apart under even the slightest degree of critical scrutiny.

Most provocatively, the courts argued that legislators had good reason for limiting marriage to opposite-sex couples because they are all too prone to producing babies “by accident or impulse.” For the sake of these casually conceived children, the courts reasoned, legislatures give opposite-sex couples an incentive to stay together: marriage, with its attendant legal and financial benefits.

Gay couples with children don’t need the same incentive to stay together, both courts reasoned, because they have to think and work harder before they can have kids. As any number of gay commentators remarked, the courts in effect said that gay couples — far from being instinctively promiscuous — are so virtuous that they don’t need the binding ties of marriage, but opposite-sex couples do.

In addition, the New York and Washington courts both said that legislators could have believed that children fare better in families with both a mother and a father as role models. Neither court had research to prove the point: There is none. Instead, as the New York court said in the main opinion, the supposed advantage was a “common sense premise” supported by “intuition and experience.”

Whatever quibbles one might raise about each of the points, both courts were guilty of an overriding lapse of logic. The issue in both cases was not whether marriage for opposite-sex couples is a good thing, but whether legislators had some reason — other than ignorance or prejudice — to deny those benefits to same-sex couples. As Chief Judge Judith Kaye wrote in dissent in the New York case, “There are enough marriage licenses to go around for everyone.”

Far from being under siege, judicial restraint appears to be very much in vogue these days — endorsed by no less a figure than Chief Justice John G. Roberts Jr. Despite Rosen’s reconstruction of history, however, the United States would have fewer freedoms and less justice today if courts always had waited for a constitutional consensus before safeguarding individual rights. And, when restraint does no more than provide cover for societal prejudice, courts dishonor their proper role by going along.

Kenneth Jost is the Supreme Court editor for CQ Press.