Jeffrey Toobin points out that personal identity has always been a factor in selecting Supreme Court justices:
In the early days of the republic, when regional disputes were the foremost conflict of the era, nominees were generally defined by their home turfs. So Presidents came to honor an informal tradition of preserving a New England seat, a Virginia seat, a Pennsylvania seat, and a New York seat on the Court. In the nineteenth century, as a torrent of European immigrants transformed American society, religious differences took on a new significance, and Presidents used Supreme Court appointments to recognize the new arrivals' growing power. In 1836, Andrew Jackson made Roger B. Taney the first occupant of what became known as the Catholic seat on the Court…. In 1916, Woodrow Wilson nominated Louis D. Brandeis, establishing the Jewish seat, which later went, with brief overlapping periods, to Benjamin N. Cardozo, Felix Frankfurter, and Abe Fortas.