Today, the Senate confirmed J. Paul Oetken to be a federal judge in the Southern District of New York. He is the first openly gay man  to be confirmed as an Article III judge (one with lifetime tenure).
In order for the federal judiciary to effectively protect our constitutional rights, the bench must reflect the diversity of America. That is not to say that demography determines how a judge will rule. But it is true that a person's background can give them insight into the effect of a law that others might miss. Ignorance of a law's actual impact can lead to a serious misanalysis of its constitutionality.
Some of the most notorious Supreme Court cases in history rest on such misunderstandings and show the results of a non-diverse bench. For instance, Plessey v. Ferguson, the 1896 case that upheld racial segregation, reflected the thinking of an advantaged class who had no real idea of how Jim Crow laws affected real people. The majority rejected out of hand
the assumption that the enforced separation of the two races stamps the colored race with a badge of inferiority. If this be so, it is not by reason of anything found in the act, but solely because the colored race chooses to put that construction upon it.
Similarly, Justice Scalia made headlines  in 2009 when he angrily challenged the assertion that non-Christians might not see a Christian cross as a symbol of respect. While they may not have changed his mind, it was good that he had non-Christian colleagues who could have given him a sense of how people different from him are affected by the law. And perhaps the notorious 5-4 Bowers v. Hardwick opinion might have been different had there been an openly gay Justice there to tell his colleagues that their assumptions about "practicing homosexuals" were simply incorrect. Surely discussions of laws impacting women are improved by actually having women on hand to offer the benefit of their experience. And judges who have been stopped for "driving while black" may recognize the real-world impact of certain police practices that might seem relatively benign to others.
A richly diverse judiciary makes it more likely that judges will understand how their decisions will affect ordinary people, and that laws protecting individuals will actually be enforced as intended. President Obama's nomination of J. Paul Oetken is part of his overall efforts to significantly increase the diversity of the bench, an effort that has, unfortunately, been met with stubborn resistance  by Senate Republicans.