The Supreme Court nominee Judge Neil M. Gorsuchdescribes himself as a constitutional “originalist.” But originalism, which we are likely to hear a lot about during his confirmation hearings this week, comes in several flavors and is more complicated than the conversation about Judge Gorsuch or the Supreme Court would suggest.

Originalists believe that faithful constitutional interpreters must build on the solid bedrock of the Constitution’s text, as that text was originally understood when drafted and ratified. For example, what did the Article III words “judicial power” mean in 1787-88? What did ratifiers of the 14th Amendment in 1866-68 understand themselves as doing when declaring that states must honor the basic “privileges” and “immunities” of American citizens?

Justice Antonin Scalia, whose seat Judge Gorsuch seeks to fill, described himself as an originalist and championed originalism on the court. Justice Clarence Thomas is also a professed originalist, as was President Ronald Reagan’s Supreme Court nominee Robert Bork.

But not all conservatives are originalists, nor are all originalists conservative. Most jurists, most of the time, follow modern judicial precedents rather than pondering first principles of constitutional text and history. Practical considerations also factor into most jurists’ decision making. Originalists are no different in this regard, but they are more apt to dwell on first principles of text and original meaning and to discard precedents violating these first principles.

The Warren court at its best was an originalist court, albeit a liberal originalist court. It overturned many precedents and rightly so. Plessy v. Ferguson flouted the Constitution’s explicit promises of racial equality; pre-Warren cases slighted the Constitution’s repeated affirmations of a “right to vote”; early-20th-century precedents ignored basic rights guaranteed by the 14th Amendment as plainly understood in the 1860s; and pre-Warren jurisprudence also undermined bedrock constitutional rights of political expression. So argued the 20th century’s greatest originalist and the Warren court’s driving force — the crusading liberal justice Hugo Black, appointed by President Franklin D. Roosevelt. Today, some of the best originalist work either comes from avowed liberals or supports various liberal outcomes. ...