It is a defining moment of an unlikely writer who means that gay, lesbian and transgender workers are protected by federal civil rights law. It is a staggering defeat for the judicial conservatives who worked to secure the nomination of Gorsuch and the Republicans, including Donald Trump, who thwarted President Barack Obama's Supreme Court candidate Liberal Merrick Garland in 2016.
The decision puts Gorsuch in the history books.
At the same time, it will infuriate those who worked on his confirmation, confident that he was the right candidate to fill Scalia's shoes.
Right after the notice was published, Carrie Severino of the curator Judicial Crisis Network lambasted Gorsuch. She said he "missed" the decision and Scalia would be disappointed.
"It was not to judge, it was to legislate - a brutal attack on our constitutional system," said Severino, who was also employed by judge Clarence Thomas.
This point was not lost on Justice Samuel Alito in his dissent, which was joined by Thomas.
"There is only one word for what the Court has done today: the legislation. The document which the Court publishes is in the form of a judicial opinion interpreting a law, but it is misleading" wrote Alito. On several occasions, in his dissidence, Alito cited earlier writings by Scalia.
"The opinion of the court is like a pirate ship," said Alito. "He sails under a textualist flag, but what he actually represents is a theory of statutory interpretation that Justice Scalia has excelled - the theory that the courts should" update "the old laws so that they better reflect the current values of the company. "
Chief Justice John Roberts and the four Liberals on the bench, Justices Ruth Bader Ginsburg, Elena Kagan, Sonia Sotomayor and Stephen Breyer joined Gorsuch. The Liberals chose not to write concurring opinions, allowing Gorsuch to ring the bell for LGBTQ rights and the judicious rejection of the Trump administration's arguments.
The vacancy that helped Trump win the White House
Scalia's death in February 2016 disrupted the presidential election. The majority leader in the Senate, Mitch McConnell, a Republican, said he would block any Obama candidate who turned out to be Garland.
Trump used the vacancy as a key factor in his base and eventual victory, and continued to tout his appointment of Gorsuch and later Brett Kavanaugh - and nearly 200 lower court judges - as achievements inherited from his presidency. .
When Trump introduced Gorsuch to the country in January 2017, under the twinkling lights of the East Room of the White House, he declared that he was fulfilling his commitment to "find the best judge in the country for the Supreme Court".
"I promised," said the president, "to choose someone who will obey our laws" and someone who "will interpret them as written." Trump nodded that Scalia and Gorsuch both saw themselves as "textualists" - interpreting the laws as they were written, relying on the text and structure of the statute instead of considering what Congress might have mean, or any legislative history associated with the law.
Gorsuch's appointment would not be easy as he would have to face the fury of the Liberals, still incandescent that the Republicans refused to hold hearings for Garland.
At the White House that night, with Scalia's widow, Maureen, in the audience, Gorsuch called Scalia a "lion of the law" and he reiterated something he would repeat over the weeks and months following: "It is the role of judges to apply, not alter, the work of representatives of the people."
Speaking at the White House, Trump called the decision "very powerful" and admitted that it was surprising to some.
"They ruled and we live with the decision," said Trump. "We are living with the Supreme Court decision."
On the bench
After taking the bench, Gorsuch wasted no time delivering for the Conservatives. He voted in favor of Trump's travel ban, and he would have allowed a citizenship question to be added to the 2020 census.
He was in the majority when the court declared that he would stay out of conflict when politicians went too far to draw district lines for partisan purposes. In one particular case, he sided with the Liberals in court in favor of an immigrant, believing that the law used against him was unacceptably imprecise. There, however, Gorsuch followed the example of Scalia, who also berated the vagueness.
In November 2017, in front of a crowd of conservatives attending the annual Federalist Society gala, Gorsuch paid tribute to Scalia's work to revitalize the way statutory and constitutional texts should be interpreted. Scalia believed that the Constitution should be interpreted according to its original public sense. He also believed that a judge should start with the text when analyzing a law and not look at legislative history or statements related to the purpose of the law.
"Tonight, I can point out that a person can be both an originalist and a publicly hired textualist and can be confirmed at the Supreme Court," Gorsuch told the thrilled crowd at the black tie. In return, they shouted their approval.
For the Liberals, Gorsuch was a sure sign of the rightward tilt of the court. In an interview with CNN last September, on the eve of the current blockbuster mandate, Gorsuch was asked specifically about the LGBTQ affair as well as about immigration and the Liberals' fear regarding the direction of the court.
In his response, Gorsuch explained how he had tackled the cases of division.
"I think all a judge can do is fulfill his oath as best he can," he said, adding, "politics, your personal views - you leave that there." .
"When you put on the dress," he continued, "you put these things aside and you open your mind, and you listen. And that's all a judge can ever promise. He can't promise of results - can only promise their best efforts in the process. "
At the time, Gorsuch was promoting his book "A Republic, if you can keep it". He exposes his judicial philosophy there. "Textualism offers judges a known and knowable methodology for impartially determining and fixing what the law is, not just declaring what it should be - a method for discerning the content of the written law without foreign value judgments about people or politics, "he wrote. .
When the court heard oral arguments in LGBT cases in October, Gorsuch alluded to the direction in which he was headed.
"When a case is very close, very close, on the textual evidence, I am with you on the textual evidence," he told David Cole, a lawyer representing a transgender claimant. "Is it close."
The Kagan factor
This line of questioning in October was also addressed by Kagan, a savvy liberal who respected and admired Scalia even though they were often on both sides of the ideological spectrum. (Scalia even suggested that Obama name Kagan when there was an opening available.)
Kagan told an audience at Harvard in 2015 that Scalia would go down in history as one of the most important historical figures in the court. She said the main reason was that Scalia had reshaped the way judges approach statutory interpretation by insisting on precise focus on the words on the page.
She noted that the approach of "textualism" could lead to different results, but that Scalia insisted that the analysis begin - at the very least - with the text and structure of the law and not something like the 'intention of Congress or committee reports and drafting of the history.
"We are all textualists now," said Kagan.
In the oral hearings in the Title VII cases, Kagan and Gorsuch appeared on the same page.
"For many years, the custodian of the statutory interpretation of this Court has been the text of a statute," she said to solicitor general Noel Francisco, representing the Trump administration, who challenged efforts to extend the scope of the Civil Rights Act.
She said that the text of Title VII which prohibits discrimination "on the grounds of" sex seemed crystal clear.
"Did you discriminate against someone," she asked rhetorically, "because of sex?"
"Yes, you did," she said, answering her own question. "Because you fired the person because he was a man who loved other men."
Francisco, a former Scalia employee, retaliated. He said it was his side that was making a "simple text argument".
For Francisco, it was simple, "the law makes a distinction between sex and sexual orientation".
"Sex means you are a man or a woman, not if you are gay or straight," he said.
Trump's other candidate, judge Brett Kavanaugh, disagreed with Gorsuch's majority opinion
While the "political arguments" for amending the law "are very important, writes Kavanaugh, and although he agrees that" gay and lesbian Americans cannot be treated as social outcasts or as inferior in dignity and worth " , he could not agree with Gorsuch's interpretation.
"We are judges, not members of Congress," Kavanaugh wrote, adding that "our role is not to make or change the law."
Go forward
It is likely that Roberts, the oldest member of the court in the majority, attributed the opinion to Gorsuch. Roberts, like other judges, often says that the press puts too much emphasis on 5-4 opinions. Indeed, Monday's opinion comes as the court is considering abortion, DACA, religious freedom and Trump's attempt to protect his financial documents. Court observers will wait to see how the court's usual bed mates line up.
As for Gorsuch, in September, he told CNN that he rejected discussions of "hard right turns" on the bench.
"I don't see judges that way, I reject this idea of how judges work," he said.
He noted that around 40% of court cases are unanimous.
"You have nine very independent people who approach these cases as best they can," said Gorusch.
This story was updated with comments from President Trump.