Which Supreme Court justice will Trump get to replace next?

As long as we’re talking Supreme Court nominations, what about the next one?

Congress hasn’t even started the fight over President Trump’s opening nominee, Federal Appeals Court Judge Neil Gorsuch. And here we are pondering the judicial apocalypse over Trump’s second nominee. The 45th president could have several pattern-setting nominations, one of the reasons many conservatives pretended to ignore his Democrat background and voted for him over what’s-her-name.

Gorsuch is 49 meaning, if confirmed, he could serve a very long time. Getting him on the bench as Antonin Scalia’s replacement would merely maintain the ideological balance existing before Scalia’s death — four conservative, four liberal and a single swing justice, Anthony Kennedy.

The prime candidate for replacement either by retirement or death now would seem to be Ruth Bader Ginsburg, by far the oldest currently serving. She was born when Franklin Roosevelt was a brand-new president, making her 84 next month after 23 years on the court as a liberal favorite.

Imagine the struggle over Trump nominating another conservative from his famous list to replace that liberal stalwart. Talk about the Senate’s nuclear option! And talk about the looming importance of the 2018 midterm elections, when Democrats must defend 23 of the 33 seats up, giving the GOP potentially a good chance of enhancing its 52-seat majority.

The stooped Ginsburg is only 5-foot-1 and 98 pounds. But she’s a toughie, having survived two bouts with cancer, either one of which could easily have been a death sentence. She was back at work just two weeks after surgery. Last year in unusual candor she shared her negative view of this Trump fellow, calling him “a faker,” among other things. He suggested she resign. She didn’t.

As a result of age and perhaps medicines, Ginsburg has been spotted in the overheated House chamber falling asleep during Barack Obama’s long State of the Union addresses. But you don’t have to be in your eighties to do that.

There’s been some muted grumbling that Ginsburg didn’t retire during Obama’s reign of error and give a liberal a chance to nominate another liberal to that life-tenure position. Too late for that.

Actually, the entire court is aging which is, we know, better than the alternative. Kennedy is 81. Stephen Breyer, another reliable liberal vote, is 79. Scalia was just shy of 80, when he died a year ago on Feb. 13. Clarence Thomas is 69. Samuel Alito is 67. John Roberts and Sonia Sotomayor are both 63. Elena Kagan is 57.

Ginsburg shows no sign of slowing further. She still makes occasional public speaking appearances. There, she’s revealed her daily exercise regimen includes sit-ups and push-ups under the guidance of the same personal trainer as Breyer and Kagan use.

But that doesn’t stop some sites from fretting over a fragile liberal whose court absence could tip the ideological balance for countless historic cases for years to come. “Eat more kale,” advised one supporter.