5 More things you need to know about the Supreme Court part 2 of 2.

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How does the nation's highest court really work? Here are more of the basics from former New York Times Supreme Court correspondent Linda Greenhouse.

The workings of the Supreme Court may seem mysterious, but the decisions its nine Justices make have a huge Impact on our daily lives.

Part 1 (Upfront, Jan. 13) covered:

1. Why do justices (jet their Jobs for life?

2. How do cases (jet to the Supreme Court?

3. How do justices decide cases?

4. Why are so many decisions 5 to 4?

5. Does the Court ever change Its mind?

1 Does public opinion influence the Court?

As the late Chief Justice William Rehnquist once said, it would be remarkable if judges were not influenced by public opinion. They live in the world, they go home to their families, they watch television, read newspapers, and many surf the Web.

The idea that the Supreme Court "follows the election returns"--that its decisions tend to move in line with popular sentiment--is true in the sense that presidents, who are elected, are likely to make at least one Supreme Court appointment. If Barack Obama had lost the 2008 presidential election to John McCain, it's a safe bet that the liberal-leaning justices, Sonia Sotomayor and Elena Kagan, would not have been appointed to fill the two most recent vacancies. A Republican president would likely have appointed conservative-leaning justices, which would have sharply shifted the Court to the right.

But does public opinion on specific issues influence the Court? Consider race. There's no doubt that the growing sense in much of the country in 1954 that segregation was fundamentally wrong paved the way for the Court's 9-to-0 ruling in Brown v. Board of Education, which barred segregation in public schools. The social revolution of the 1960s and the widespread entry of women into the workplace certainly played a role in the Court's decisions, beginning in the early 1970s, prohibiting discrimination against women. The Defense of Marriage Act, passed by Congress in 1996, barred same-sex couples married under state law from receiving the same federal benefits heterosexual couples get. It's quite possible the Court wouldn't have struck down the law last year if a dozen states hadn't already legalized same-sex marriage by the time the justices rifled.

As former Justice Benjamin N. Cardozo observed in the 1920s, "The great tides and currents which engulf the rest of men do not turn aside in their course and pass the judges by."

2 Has the presence of women and minorities changed the Court?

Until Thurgood Marshall, who was black, was sworn in as the 96th justice in 1967, only white men had sat on the Supreme Court. With a few exceptions, the justices were all Protestants. In the 47 years since, things have changed dramatically.

The Court today consists of one African-American (Clarence Thomas); one Hispanic (Sotomayor); six Catholics (John G. Roberts Jr., Anthony M. Kennedy, Antonin Scalia, Samuel Alito, Thomas, and Sotomayor); three Jews (Ruth Bader Ginsburg, Stephen G. Breyer, and Kagan); and three women (Ginsburg, Sotomayor, and Kagan).

The look of the Court has certainly changed, but a justice's race or gender doesn't necessarily predict his or her legal reasoning. Justices Thomas and Marshall, though both black, could not be...