For a half century, presidential candidates have routinely claimed that there are no bigger stakes in the election than the next appointments to the Supreme Court. This year, for the first time since 1968, the dire warnings could actually have an important effect on voting behavior.

Since the death of Justice Antonin Scalia in February, the court has deadlocked 4-4 on four cases. On a number of others, a single vote determined the outcome. In addition, Merrick Garland, the nominee to release to replace Scalia, will still be waiting for review by the Senate on Election Day; two justices will be in their 80s, and one will be 78.

It is likely that Hillary Clinton or Donald Trump will have at least two or three appointments in a first term. And that will shape a number of important issues, ranging from immigration to racial preferences, as well as the role of unions and environmental issues.

The last time there was an open seat during a presidential election was 1956. That October, President Dwight D. Eisenhower tapped William Brennan in a recess appointment for the slot. In 1968, Chief Justice Earl Warren declared his intention to step down, but President Lyndon Johnson’s choice to succeed him, Justice Abe Fortas, was blocked by the Senate.

This year, both candidates are seizing on the issue. Trump has released a list of 10 conservative jurists he might consider for court vacancies.

Clinton hasn’t gone that far, but she has vowed that any appointee would favor abortion rights and overturning the court’s recent campaign finance decisions.

She once said that she’d love to name Obama to the bench — William Howard Taft became chief justice after he left the White House — but that’s unlikely.

As president, she probably would like to tap someone younger, more liberal and of a more diverse background than the 63-year-old Garland, who was first nominated in March. But to pass him over would be a rebuke not only to the respected judge, but also to Obama. That’s probably not the way she’d like to start a presidency.

Activists on the right and left are ginned up and certainly will make the court part of their fundraising.

Conservatives have done a slightly better job of seizing on the issue. They may be helped this time by court decisions on affirmative action, abortion, same-sex marriage and upholding Obamacare that the right found disappointing.

Meanwhile, liberals hope Trump will stir their base, especially Hispanics. One of the deadlocked Supreme Court decisions this term effectively suspended President Barack Obama’s executive order aimed at preventing millions of undocumented workers from being deported. It likely will be considered again.

Albert Hunt is a Bloomberg columnist.