STEPHEN L. CARTER: Hillary Clinton and the New Litmus Test.

You might have missed the news that John Paul Stevens, the retired U.S. Supreme Court justice, criticized Democratic presidential front-runner Hillary Clinton last week for her announcement that she would nominate to the court only individuals committed to overturning the 2010 decision in Citizens United v. Federal Elections Commission. Stevens doesn’t like the decision any more than she does — his dissent ran to 90 pages — but he likes litmus tests even less.

At a house party in Mason City, Iowa, a few days after offering her promise, Clinton doubled down: “I will do everything I can do to appoint Supreme Court justices who will protect the right to vote and not the right of billionaires to buy elections,” she said.

Stevens, in remarks last week at George Washington University, was unimpressed: “I’m not really sure that that’s wise either for the court or for a presidential candidate to make a litmus test on one particular decision. … I’m surprised at her statement.” The former justice added: “If I were running for president, I don’t think I would make such a litmus test, even though I think the case ought to be overruled.”

Stevens is right. I won’t trouble here to go into the reasons for my own longstanding opposition to litmus tests, other than to note that there is something decidedly peculiar about promising to place on the Supreme Court individuals who have already decided the cases to come before them.

Read the whole thing.