In a move that could transform the Supreme Court for decades, Justice Anthony Kennedy has announced his retirement, giving President Trump a chance to pick a second conservative on the high court. Kennedy, who was nominated by President Reagan, was widely seen as the swing vote on the nine-justice court. On Wednesday, he sided with the conservative wing of the court to deal a major blow to public-sector unions in the case of Janus v. AFSCME. He also sided this week with the majority upholding President Trump’s Muslim travel ban. But Kennedy has sided with the liberal wing of the court on a number of pivotal issues. He has been instrumental in preventing Roe v. Wade from being overturned, and he has supported same-sex marriage, affirmative action and criminal justice reform. On Wednesday, President Trump said he wants to pick a justice who will be on the court for the next 40 or 45 years. DN! speaks to Dahlia Lithwick, senior editor at Slate.com.