A Supreme Court nominee must be confirmed by the Senate in order to be appointed by the president. But for months now the Republican-controlled Senate has refused to consider the nomination of Judge Merrick Garland, President Obama's choice to fill the seat opened by the death of Justice Antonin Scalia. There have been no hearings and no votes—only one-on-one meetings with some senators.

"I would hope that the Senate would do its job," said Hillary Clinton during the debate last night, "and confirm [Garland]. That's the way the Constitution fundamentally should operate. The president nominates and then the Senate advises and consents or not, but they go forward with the process."

There are some things wrong with this. The Constitution doesn't say what the Senate's "job" is but leaves that question to the upper chamber. Granted, thanks to the practice in recent decades, we are used to a confirmation process that includes hearings and votes providing consent or denying it. But the Senate is free to do as it thinks best in exercising its consent power.

Here it has done so by refusing to process the Garland nomination during an election year in order to let voters decide who gets to nominate Scalia's successor—Clinton or Donald Trump. Of course, the next president will also get to fill other vacancies that might open during the next four years. Clearly, the future of a Court that leans in a liberal direction is at stake.

Both parties are urging voters to take that into account when casting their ballots for not only president but also for the 34 Senate seats that are up this year, 24 of which are held by Republicans. Yet if the Republicans, now holding 54 seats, fail to retain their majority, they still may be able to block a Clinton nominee, since confirmation of a Justice requires at least 60 votes. Going forward "with the process" is no guarantee of a nominee's confirmation.