Erwin Chemerinsky is dean and Jesse H. Choper Distinguished Professor of Law at the University of California, Berkeley, School of Law. He is the author of "The Case Against the Supreme Court." The opinions expressed in this commentary are solely those of the author.

(CNN) The irony of Justice Anthony Kennedy's legacy probably will be that the areas where he made the greatest difference in the law are the ones that are least likely to survive in the new, resolutely conservative Supreme Court poised to emerge under President Donald Trump.

Erwin Chemerinsky

Justice Clarence Thomas is 70; Samuel Alito is 68; John Roberts is 63; Neil Gorsuch is nearly 51. Absent unforeseen circumstances, they and the new nominee will be the majority for the next 10 to 20 years. For conservatives, this is a time to rejoice. For liberals, it is devastating.

Kennedy came on to the court after the Senate rejected the confirmation of a more conservative nominee, Robert Bork. Although overall Kennedy was more likely to side with the conservatives than the liberals in his 30 years on the court, there were many areas where he was notably more liberal than Bork would have been as a justice. It is expected that Kennedy will be replaced by someone who will be more consistently conservative, and these are the very areas where the law is likely to move to the right.

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His most notable contribution to the law has been in the area of gay and lesbian rights. Kennedy has written every Supreme Court decision in history advancing rights for gays and lesbians. For example, in 2013, he authored the decision declaring unconstitutional a key provision of the federal Defense of Marriage Act, and in 2015, he wrote the opinion declaring unconstitutional state laws prohibiting same-sex marriage. Both were 5-4 decisions. I am surprised this is regarded as settled law in light of the vehement dissents, especially by Chief Justice John Roberts.

Kennedy was famously the fifth vote in 1992 in Planned Parenthood v. Casey to reaffirm Roe v. Wade. At the time, Bork publicly declared that he would have come out the other way. Two years ago, Kennedy was the fifth vote to strike down a Texas law imposing restrictions on access to abortion. But his replacement likely will join with the four conservative justices -- Roberts, Thomas, Alito and Gorsuch -- and overrule Roe and allow states to prohibit all abortions.

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