It has been widely noted that Supreme Court Justice David Souter proved a disappointment to the Republicans who had supported his confirmation in 1990. The cause of this disappointment was not that Souter turned out to have a complex and nuanced jurisprudence that deviated from the party line. Nor was it that Souter had more respect for precedent than other Republican appointees — a laughable theory that various reporters have assayed in the days since Souter announced he would retire. Souter ended up being an extremely predictable vote for the left wing of the Court, and his attitude toward precedent mostly depended on whether precedent would yield liberal policy results.

More often than not, he took issues that the Constitution leaves to be decided by the democratic process and voted to impose liberal solutions. His votes on everything from school vouchers to gay rights to the death penalty to national-security law followed that pattern. His opinions were neither insightful, eloquent, or otherwise memorable. He assumed vast imperial powers but issued his commands in a plodding bureaucratese.

The papers are now full of speculation about Souter’s replacement, complete with fine distinctions among different species of liberals that will make almost no difference in how the eventual justice votes. President Obama says that he is looking for someone who will have “empathy” for, among others, single mothers and gays. He is not looking for someone with empathy for small-business owners: Empathy is simply a codeword for an inclination toward liberal activism. Obama announced during the campaign that he would also look for someone loyal to Roe v. Wade rather than to the Constitution it traduced. “News analyses” stress that Obama is a “pragmatist” who does not care about high-flown legal theories. Just so: He cares about getting another vote for liberal results.

Those of us who believe in the “theory of originalism” — what was once called, simply, “judging” — have little leverage. The Democratic Senate will be a rubber stamp for Obama. Republicans should nonetheless press for an extended debate about the extent to which judges have supplanted self-rule and the role of modern liberalism in that slow-motion coup. (Is there something else they would rather this Congress spent its time on?)

Republicans have grown attached to their own misbegotten theory of judges: that presidential picks deserve deference so long as they have the right credentials and no major ethical lapses. This political norm made sense in an era when judges stayed within their constitutional authority. In our time, it makes constitutionalist senators complicit in the erasure of the Founders’ legacy. It doesn’t even calm the waters. Republicans let President Clinton’s Supreme Court appointees skate by with nearly unanimous consent, and in return got eight years of filibusters during the next GOP presidency.

Unless Obama does something truly shocking, such as appointing a liberal committed to following the original understanding of the Constitution and its amendments, the proper course for Republicans — inside and outside the Senate — is to build a case for saying no.