"Justice Kennedy’s retirement is the biggest event in U.S. jurisprudence in at least 15 years"

- Jack Goldsmith, WaPo

Supreme Court Justice Anthony Kennedy is retiring from the United States Supreme Court, effective July 31.

Nominated by President Reagan in 1987, the 81-year-old conservative justice leaves the bench after more than three decades of service - the 14th longest serving justice (out of 113) in Supreme Court history, leaving a vacant seat to be filled by a Trump appointee. His retirement has been long anticipated, though recent comments he made this week as the court upheld the President's "travel ban" suggested an imminent departure from the bench according to Slate's Richard Hasen.

Since at least 2005, Kennedy - a conservative considered to the left of Trump, has been the swing vote on some of the Court's most controversial decisions - and has been responsible for several 5-4 rulings, such as the legalization of same-sex marriage, the preservation of Roe v. Wade, the upholding of warrantless wiretapping, and the overturning of Washington D.C.'s handgun ban.

Kennedy's retirement comes a year after Justice Neil Gorsuch's confirmation to replace Justice Antonin Scalia.

Without Kennedy, the court will be split between four liberal justices who were appointed by Democratic presidents and four conservatives who were named by Republicans. Trump’s nominee is likely to give the conservatives a solid majority and will face a Senate process in which Republicans hold the slimmest majority, but Democrats can’t delay confirmation.

His departure will give conservatives hope that his replacement will be a more "reliable" conservative, creating the most conservative court in generations - while Trump has pointed to a list of 25 potential nominees assembled with the assistance of the Heritage Foundation and the Federalist Society.

The oldest Justice, 85-year-old Ruth Bader Ginsburg, has made it clear she won’t reretire any time soon, particularly while Donald Trump is president. Here are the ages of all SCOTUS judges:

Roberts, 63

Kennedy, 81

Thomas, 70

Ginsburg, 85

Breyer, 79

Alito, 68

Sotomayor, 64

Kagan, 58

Gorsuch, 50

Kennedy, an 81-year-old Ronald Reagan appointee, has been the court’s pivotal vote for the last decade, and as Bloomberg reports, his centrist position meant he wrote some of the court’s most important opinions.

He disappointed conservatives in 1992, when he co-wrote an opinion reaffirming the constitutional right to abortion. Although he later backed some restrictions -- voting to uphold a federal ban on some late-term abortions -- he cast the decisive vote to strike down Texas regulations on clinics and doctors in 2016. Kennedy became a champion of gay rights and wrote the 2015 ruling that legalized same-sex marriage nationwide, using the type of sweeping language that characterized his opinions. “No longer may this liberty be denied,” Kennedy wrote. “No union is more profound than marriage, for it embodies the highest ideals of love, fidelity, devotion, sacrifice and family.” Kennedy also wrote the 2010 Citizens United ruling, which opened the way for a torrent of new campaign spending. He equated campaign-finance laws with censorship, writing that "the First Amendment confirms the freedom to think for ourselves." He was the quintessential swing vote on racial issues. He joined the conservative wing to strike down a core provision of the Voting Rights Act in 2013 but voted with the court’s liberals in 2016 to back university affirmative action programs. Kennedy voted to overturn then-President Barack Obama’s health-care law. He was one of five justices in the majority of the 2000 Bush v. Gore ruling, which sealed George W. Bush’s election as president over Democrat Al Gore.

Potential replacements include Washington-based federal appeals court judge Brett Kavanaugh, a former Kennedy law clerk with close ties to the retiring justice. Kavanaugh is a longtime Washington insider, having served as a law clerk to Kennedy and then as a key member of independent counsel Kenneth Starr’s team that produced the report that served as the basis for President Bill Clinton’s impeachment. In October, Kavanaugh dissented when his court ruled that an undocumented teen in federal custody should be able to obtain an abortion immediately.

Trump could also consider three federal judges he interviewed before selecting Neil Gorsuch to fill an earlier vacancy: William Pryor of Alabama, Thomas Hardiman of Pennsylvania and Amul Thapar of Kentucky.

Other possibilities include federal appellate judges Raymond Kethledge of Michigan, who was considered for the Gorsuch seat but didn’t get an interview, and Amy Coney Barrett of South Bend, Indiana.

As Bloomberg notes, all are on a list of 25 prospective justices the White House has developed with input from the conservative Federalist Society and Heritage Foundation.

Republicans hold a 51-49 advantage in the Senate, so they could approve Trump’s nominee without any Democratic support. In confirming Gorsuch, Republicans eliminated the 60-vote requirement to advance a Supreme Court nomination.

Abortion is likely to be one of the flash points in the nomination fight according to the AP. Kennedy has mainly supported abortion rights in his time on the court, and Trump has made clear he would try to choose justices who want to overturn the landmark abortion rights case of Roe v. Wade. Such a dramatic step may not be immediately likely, but a more conservative court might be more willing to sustain abortion restrictions.

According to Vox, here's what will and won't change in a post-Kennedy Supreme Court:

The Court’s decisions on issues where he’s a down-the-line conservative — like campaign finance and corruption, most business regulation and voting cases, gun rights, religious liberty, etc. — likely won’t change. There’s already a 5-4 conservative majority on those, so conservative rulings like the ones Kennedy wrote or joined in DC v. Heller, Citizens United, or Hobby Lobby will continue apace. What will change are rulings on issues where Kennedy has helped maintain a shaky 5-4 center-left consensus. Because of the court’s longstanding principle of stare decisis, or obeying past precedent barring a compelling reason not to do so, some liberal Court achievements are likely to stay. But a Court without Kennedy is substantially more likely to: Overturn Roe v. Wade and allow states (and maybe the federal government too) to ban most or all abortions.

Reject challenges to capital punishment and solitary confinement.

Rule in favor of religious challenges to anti-discrimination law, and perhaps, in an extreme case, reverse some past Supreme Court rulings on gay rights.

Bar government actors from engaging in explicit race-based affirmative action. And there are likely to be more aftershocks that are hard to anticipate this far in advance.

Needless to say, Trump was ready saying that Kennedy will be missed, and that a search for his replacement will begin immediately form a list of 25 possible replacements:

TRUMP SAYS HE'S RESPECTED JUSTICE KENNEDY, HE WILL BE MISSED

TRUMP: WILL BEGIN SEARCH FOR KENNEDY REPLACEMENT IMMEDIATELY

TRUMP SAYS HE HOPES KENNEDY IS AROUND FOR A LONG TIME TO ADVISE

TRUMP SAYS HE HAS LIST OF 25 PEOPLE FOR POSSIBLE COURT PICKS

WATCH: Pres. Trump makes remarks following retirement announcement of Anthony Kennedy from the Supreme Court. https://t.co/h6JwM9o4G8 — ABC News (@ABC) June 27, 2018

As a reminder, this strategic change will bring the Republicans even more together ahead of the Midterms...

This is a huge rallying call for GOP midterm votes. You better vote for us or they'll block our SCOTUS pick. — im not here, see note in profile 🗽 (@Anthony) June 27, 2018

To be sure, Democrats, liberals and progressives - facing another Supreme Court seat loss - are furious. In the tweet below, listen to DNC Rules committee members groan "Oh my God!" and "This is not good news."

LISTEN: DNC Rules committee members groan "Oh my God!" and "This is not good news," upon learning of Justice Kennedy's retirement. pic.twitter.com/SkSVnqlyDr — Josh Caplan (@joshdcaplan) June 27, 2018