While Republicans (and many reporters) are complaining that Hillary Clinton has been unwilling to answer questions from the press, there’s one thing she seems to be clear about. Appearing at an event in Iowa, she said: “I will do everything I can to appoint Supreme Court justices who protect the right to vote and do not protect the right of billionaires to buy elections.”

While this is being reported as a “litmus test” that anyone she considers appointing would have to be committed to overturning the Citizens United ruling, it isn’t quite that. “I will do everything I can” isn’t as categorical as “I promise to appoint only justices who agree that…” But if Clinton wants to make Citizens United a litmus test, she should go right ahead. Litmus tests get a bad rap, but they might be just what we need.

There’s a charade we go through every four years, in which the presidential candidates assure us that when it comes time to pick Supreme Court justices, the substance of our most contentious policy debates will not enter their minds at all. Instead, they’ll be looking only for justices who are experienced and wise, full of modesty and respect for the Constitution. All will insist that they have no litmus tests, because that would be wrong.

Then when someone actually gets appointed to fill a seat, they repeat the same disingenuous line in their confirmation hearings — particularly if they’re Republican and the topic is abortion. They come before the Senate claiming to have no settled opinions about anything, committed only to objective analysis of the facts and the Constitution. As Chief Justice John Roberts said in his confirmation hearing, “It’s my job to call balls and strikes, and not to pitch or bat.”

Right now there are four justices on the Court — Roberts, Antonin Scalia, Clarence Thomas, and Samuel Alito — who are committed to overturning Roe v. Wade. It’s only a question of getting that fifth vote, and once they do, it will be done. Everyone, Republicans and Democrats alike, understands that to be true. Yet all four of them were asked explicitly about the case in their hearings, and all bobbed and weaved to avoid saying they would do what both their supporters and their opponents knew they would.

“I assure you, I have no agenda,” said Scalia. “I am not going onto the Court with a list of things that I want to do. My only agenda is to be a good judge.” When pressed on Roe, he insisted that while there are many laws he might personally disagree with, he could still uphold them if the Constitution so demanded. John Roberts met every question about Roe with a rambling, abstract discussion of stare decisis, the principle that the Court should respect its prior decisions.

When confronted with documents in which he had written explicitly that Roe ought to be overturned, Alito insisted that it wouldn’t matter: “That was a statement that I made at a prior period of time when I was performing a different role, and as I said yesterday, when someone becomes a judge, you really have to put aside the things that you did as a lawyer at prior points in your legal career and think about legal issues the way a judge thinks about legal issues.”

Most remarkably, Clarence Thomas stated that on what is perhaps the most contentious legal issue of the last half-century, he not only had no opinion at all, he had never even had a conversation about it. “Senator, your question to me was did I debate the contents of Roe v. Wade, the outcome in Roe v. Wade, do I have this day an opinion, a personal opinion on the outcome in Roe v. Wade; and my answer to you is that I do not.”

For the record, the current liberal justices, when asked the same question, just said that Yes, they support Roe. But let’s be clear about the conservatives: every one of them was trying their best to deceive the Senate and the public about what they thought. And though few people were really fooled, it was good enough to get them confirmed.

This really goes back to the last Supreme Court justice who turned out to be ideologically different from what the president who appointed him expected him to be. David Souter was plucked from relative obscurity by George H.W. Bush in 1990, and when he turned out to be a stalwart of the Court’s liberal wing, conservatives made “no more Souters!” a rallying cry. Democrats learned a lesson, too: you have to be absolutely clear about the beliefs of the justices you appoint, even as the president and the potential justices themselves maintain the fiction that they could rule either way on any issue, because they have no policy agenda or ideological beliefs.

Given the age of the justices, the potential for the next president to dramatically swing the Court’s direction, and the enormously consequential issues the Court decides each and every year, the question of the Supreme Court may be the single most important issue in the 2016 election. The truth is that every candidate has his or her litmus tests — they just aren’t telling us what they are. It’s possible that Jeb Bush’s litmus tests are different from Scott Walker’s litmus tests or Marco Rubio’s litmus tests. If you were a Republican primary voter, wouldn’t you want to know how?

The candidates should be honest and say: “Here are the three (or five, or ten) issues on which anyone I appoint to the Supreme Court must agree with me.” You can decry the partisanship of the Court all you want, but that partisanship will be a reality no matter what the candidates say. At least if they were forthcoming, we’d know what we’re going to get, and everyone could vote accordingly.