Correction: An earlier version of this column incorrectly stated that Plessy v. Ferguson was decided by the Supreme Court on an 8 to 1 decision. The decision was 7 to 1; Justice David J. Brewer did not participate in the case. The version below has been corrected.

In 1966, the Supreme Court set a convicted rapist free because the police didn’t offer him a lawyer before he confessed to the crime.

The confession was not ­coerced, and the police had otherwise acted properly under existing law. Nevertheless, the court created a new requirement to “read ’em their rights” and imposed it nationwide.

Conservatives warned that activist justices had set the stage for a new crime wave. To opponents, the ruling was all the more illegitimate because it was decided by a vote of 5 to 4.

Today, Miranda v. Arizona is deeply embedded in U.S. constitutional law, widely accepted by police and public alike. Given the opportunity to overrule Miranda in 2000, the Supreme Court voted 7 to 2 to affirm it. The majority opinion, by erstwhile Miranda critic Chief Justice William H. Rehnquist, noted that “the warnings have become part of our national culture.”

I recite this history in anticipation of the outcry that may greet a 5 to 4 ruling in the pending health-care case.

Like others, I’ve worried that a one-vote majority in such a pivotal matter might harm the court’s legitimacy. But a closer reading of history, both distant and recent, suggests otherwise.

The myth is rooted partly in reality: namely, Chief Justice Earl Warren’s efforts to assemble a 9-to-0 majority behind the landmark Brown v. Board of Education ruling in 1954, so as to insulate the court from a Southern backlash against school desegregation.

In fact, Warren’s efforts were only partly successful, since Southern states attempted “massive resistance” for years anyway. Brown endured because it was right, and because the federal government backed it, not because it was unanimous.

Conversely, the “separate but equal” doctrine that Brown supplanted is now thoroughly discredited, even though the 1896 ruling that established it, Plessy v. Ferguson, was decided 7 to 1. Several notorious Reconstruction-era decisions that curbed or eliminated federal power to defend civil rights were decided 9 to 0 or 8 to 1.

West Coast Hotel v. Parrish, the 1937 ruling that overturned previous conservative anti-regulation doctrine — and ended the court’s opposition to New Deal laws — was a 5 to 4 decision. Yet, like Brown and Miranda, it has stood the test of time.

So much for history. But what about public acceptance of 5 to 4 rulings in their own time?

There’s a big difference between an unpopular decision and a decision that delegitimizes the court.

A February 2010 Washington Post/ABC News poll found that 65 percent of the public “strongly opposed” the court’s 5 to 4 ruling in Citizens United v. Federal Election Commission, which overturned an act of Congress limiting corporate and union campaign contributions. This is one reason President Obama and other Democrats felt free to criticize the court’s finding.

Yet Citizens United did no apparent damage to public confidence in the Supreme Court. A 2011 survey funded by Washington University in St. Louis found that 22.3 percent of the public still had a “great deal” of confidence in the court — double the rate for the Congress whose law the court had just struck down. Only 7.1 percent expressed “hardly any” confidence in the justices, in contrast to 29.7 percent and 29 percent who felt that way about Congress and President Obama, respectively.

As Washington University political science professor James L. Gibson writes, public confidence in the court is “obdurate.” Decades worth of data show that it does not ebb and flow with the short-term popularity of its decisions, much less with the size of a court majority.

Rather, the justices are esteemed because of their perceived expertise, the relative impartiality of their deliberations (compared to the political branches) and because the court symbolizes “the rule of law.”

But what if the court seems to split 5 to 4 along partisan lines, as some predict for the health-care case? Even that would not erode its standing, as long as most people either agree with the outcome or generally see the court as final arbiter even when they disagree with it. Usually, Gibson argues, a majority does indeed hold at least one of those views. Though the current court leans a bit right, it produces enough “liberal” results — 42 percent of the time in its 2010-2011 term, according to Gibson — to preserve a reputation for fairness.

The public still esteemed the court after five GOP-appointed conservative justices all but handed the presidency to George W. Bush in 2000 — contrary to many legal academics’ predictions that the decision was legally flawed and therefore a partisan blot on the court.

However the justices rule on health care, and however they split, there will be a political storm. But the court will probably weather it.