Bernie Sanders said last night: “No nominee of mine, if I’m elected president, to the United States Supreme Court will get that nomination unless he or she is loud and clear, and says they will vote to overturn Citizens United.”
Democrats have generally been less inhibited than Republicans about imposing explicit litmus tests on judicial nominees. The last two Democratic presidents have said that their nominees would support Roe v. Wade and its progeny. Republicans have not made the reverse pledge.
In his book on his time as President George H. W. Bush’s chief of staff, John Sununu suggested that Bush wanted his Supreme Court appointments to vote to overturn Roe v. Wade. But Sununu also indicated that nobody interviewing him insisted on getting a commitment from David Souter on the point. Some pro-lifers wanted George W. Bush to commit to getting commitments when he first ran for president, but his campaign rebuffed them, suggesting that it would be improper to seek them—and that, anyway, a nominee who had made such commitments would have to say so to the Senate and thus jeopardize his confirmation.
The leading Republican presidential candidates have said that Roe v. Wade was wrongly decided, and most have also said it should be overturned. They have not, however, said that they would insist that their Supreme Court nominees promise to vote that way.