Supreme Court Justice Anthony Kennedy announced his retirement Wednesday, setting the stage for what promises to be an epic political battle over his replacement.
A Trump nominee is likely to be far more conservative than Kennedy, who, though appointed by President Reagan, voted with the court's liberals in some key cases.
Kennedy, who will turn 82 next month, made the announcement one day after the court handed down its last pending opinion for the 2017-18 term. He said he would continue to serve through July 31 of this year.
There is little doubt about Kennedy's mark on history. Quite simply, he remade the face of marriage in America. More than any other justice, he was responsible for the advancement of LGBT rights. He wrote four of the court's opinions on the subject over nearly two decades, and ultimately declared marriage between two people of the same sex a fundamental right protected by the Constitution.
"No union is more profound than marriage, for it embodies the highest ideals of love, fidelity, devotion, sacrifice, and family," Kennedy said in his opinion. "In forming a marital union two people become something greater than what they once were."
On a court that has become increasingly conservative, Kennedy's role has been pivotal. In 5-to-4 decisions, his vote has usually determined the outcome on some of the hottest legal and social issues of the day not just gay rights, but abortion, campaign finance, gun rights, affirmative action, the war on terror and the death penalty.
President Trump has pledged to nominate a replacement who will almost certainly vote differently on many of these issues, putting some landmark decisions in jeopardy from Roe v. Wade to the legalization of same-sex marriage.
That will please and reward conservative groups that have supported him. At the same time, it will galvanize opposition among Democrats, and potentially even some moderate Republicans.
The confirmation rules this time, however, will be different from the get-go. When Democrats threatened to delay Trump's first nominee, Neil Gorsuch, earlier this year, Republicans voted to exempt Supreme Court nominations from filibusters, which required a super-majority of the Senate to cut off debate.
So this time, the president will make his choice knowing that he only needs to get a majority of the Republican-controlled Senate to approve his nominee. And Senate Majority Leader Mitch McConnell, R-Ky., has proven adept at keeping his troops in line on judicial nominations.
Still, the pressure will be intense, and the stakes high.
If anyone has doubts about how different the court would likely be when a centrist conservative like Kennedy is replaced by someone more hard-line, there is the example of Justice Sandra Day O'Connor's retirement in 2006. President George W. Bush chose Samuel Alito to replace O'Connor, and the effect has been profound; O'Connor has even complained privately that Alito is systematically dismantling her legacy.