One wonders why he is still a judge?
I see absolutely no value to a judge of spending decades, years, months, weeks, day, hours, minutes, or seconds studying the Constitution, the history of its enactment, its amendments, and its implementation (across the centuries—well, just a little more than two centuries, and of course less for many of the amendments). Eighteenth-century guys, however smart, could not foresee the culture, technology, etc., of the 21st century. Which means that the original Constitution, the Bill of Rights, and the post–Civil War amendments (including the 14th), do not speak to today. David Strauss is right: The Supreme Court treats the Constitution like it is authorizing the court to create a common law of constitutional law, based on current concerns, not what those 18th-century guys were worrying about.
Why hasn't he been dismissed? (or shot for abandoning his oath...?)
In the United States, federal judges are required to take two oaths. The first oath is this:
I, (name), do solemnly swear (or affirm) that I will administer justice without respect to persons, and do equal right to the poor and to the rich, and that I will faithfully and impartially discharge and perform all the duties incumbent upon me as (office) under the Constitution and laws of the United States. [So help me God.]
The second is the same oath that members of Congress take:
I, (name), do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter. [So help me God.]
Federal statute specifically says that the latter oath "does not affect other oaths required by law."