President Trump nominated Colorado federal appeals court judge Neil Gorsuch for the Supreme Court on Tuesday, opting in the most important decision of his young presidency for a highly credentialed favorite of the conservative legal establishment to fill the opening created last year by the death of Justice Antonin Scalia.

Gorsuch, 49, prevailed over the other finalist, Thomas Hardiman of Pennsylvania, also a federal appeals court judge, and Trump announced the nomination at a televised prime-time event at the White House.

The bonhomie of the ceremony was in stark contrast to the reaction of Democrats, who are ready for a pitched battle over the future of the Supreme Court. Senate Minority Leader Charles E. Schumer (D-N.Y.) said Gorsuch will have to win over some Democratic senators to get the 60 votes needed to clear procedural hurdles.

Trump broke tradition by entering the White House ceremony by himself, rather than alongside his nominee. He declared that after “what may be the most transparent judicial selection process in history,” he had delivered on a campaign promise to “find the very best judge in America” for the court.

Gorsuch took a humbler approach, and showed the flair for language that has won him praise as a legal writer.

“Standing here in a house of history, and acutely aware of my own imperfections, I pledge that if I am confirmed I will do all my powers permit to be a faithful servant of the Constitution and laws of this great country,” said Gorsuch, with his wife Louise at his side.

Gorsuch pledged to be impartial and independent, and respectful of his place in government.

“It is the role of judges to apply, not alter, the work of the people’s representatives,” he said. “A judge who likes every outcome he reaches is very likely a bad judge.”

Gorsuch’s pick won extravagant praise from Republicans and conservatives, something that has been rare in the Trump administration’s combustible start. The president noted that Gorsuch had been confirmed to the U.S. Court of Appeals for the 10th Circuit 10 years ago without objection.

“I can only hope that both Democrats and Republicans can come together for once for the good of the country,” Trump said.

That is unlikely. Democrats and liberals are still furious that the Republican Senate did not allow a vote on former President Barack Obama’s choice for the Scalia seat, Judge Merrick Garland, and vowed to contest Gorsuch.

An early sign of discontent: Trump invited senior Democratic senators to the White House for a reception to meet his Supreme Court pick, but they declined, according to senior aides.

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A group of legal and civil rights groups blasted the nomination, saying Gorsuch was a tool of conservative activists who would gut protections for consumers, workers, clean air and water, safe food and medicine and roll back the rights of women and LGBT people.

Gorsuch and Hardiman, 51, emerged from a list of 21 as Trump’s most likely choices. A third person on the shortlist — U.S. Appeals Court Judge William H. Pryor Jr. of Alabama — saw his chances diminish as some Senate Republican leaders have said his confirmation would be difficult.

Trump considered six and met with four, including a federal district judge from Kentucky, Amul R. Thapar.

Gorsuch got the word Monday, and the couple went to a neighbor’s house in Boulder, where they were met by a team from the White House Counsel’s Office. They were ferried along a country road to the airport, where they boarded a military jet to Washington.

[Read speeches and key cases of Supreme Court nominee Neil Gorsuch]

Gorsuch is seen as a less bombastic version of Scalia and would seem destined to be a solidly conservative vote on the ideologically split court. But friends and supporters describe Gorsuch as being more interested in persuasion than Scalia, who was just as likely to go it alone as to compromise.

Gorsuch would be the youngest Supreme Court justice since Clarence Thomas was confirmed in 1991. But Gorsuch has been on the bench for a decade, and at his 2006 investiture ceremony, friends joked that his prematurely gray hair was fitting.

“When Neil came to our firm in 1995 he had gray hair,” said one of his law partners, Mark C. Hansen. “In fact, he was born with silver hair, as well as an inexhaustible store of Winston Churchill quotes.”

Indeed, Gorsuch came equipped for the ultimate judicial elevation.

There is a family connection to Republican establishment politics, and service in the administration of George W. Bush. There is a glittery Ivy League résumé — Columbia undergrad, Harvard Law — along with a Marshall scholarship to Oxford. There is a partnership at one of Washington’s top litigation law firms and a string of successful cases.

There is a Supreme Court clerkship; Gorsuch was hired by Justice Byron White, a fellow Colorado native, who shared him with Justice Anthony M. Kennedy.

Kennedy stood by that day in Denver to administer the judicial oath, and if Gorsuch is confirmed, Kennedy would become the first justice to sit with a former clerk on the Supreme Court’s mahogany bench.

But those who know Gorsuch and have studied his decade of solidly conservative opinions on the Court of Appeals say he more resembles the man he would replace — the late Justice Scalia — than the more moderate Kennedy.

Like Scalia, Gorsuch is a proponent of originalism — meaning that judges should attempt to interpret the words of the Constitution as they were understood at the time they were written — and a textualist who considers only the words of the law being reviewed, not legislators’ intent or the consequences of the decision.

Critics say that those neutral considerations inevitably lead Gorsuch to conservative outcomes, a criticism that was also leveled at Scalia.

Gorsuch would like to curb the deference that courts give to federal agencies and is most noted for a strong defense of religious liberty in cases brought by private companies and religious nonprofit groups objecting to the contraceptive mandate in the Affordable Care Act.

Gorsuch said in a speech last spring that as a judge he had tried to follow Scalia’s path.

“The great project of Justice Scalia’s career was to remind us of the differences between judges and legislators,” Gorsuch told an audience at Case Western Reserve University School of Law in Cleveland.

Legislators “may appeal to their own moral convictions and to claims about social utility to reshape the law as they think it should be in the future,” Gorsuch said. But “judges should do none of these things in a democratic society.” Instead, they should use “text, structure and history” to understand what the law is, “not to decide cases based on their own moral convictions or the policy consequences they believe might serve society best.”

But those who know him say he lacks Scalia’s combustible, combative style.

“He has very strong opinions, but he just treats people well in every context,” said Melissa Hart, a University of Colorado law professor. She is a Democrat who clerked for former Justice John Paul Stevens and knows Gorsuch because he has taught judicial ethics, legal writing and antitrust law at the school.

Gorsuch was born in Colorado and lives outside of Boulder with his wife, Louise, whom he met while at Oxford, and two daughters. The nominee is an Episcopalian, and would be the court’s only Protestant. There are five Catholic and three Jewish members.

But he spent formative years in Washington and graduated from Georgetown Prep. He witnessed firsthand how difficult Washington politics can be. His mother was Anne Gorsuch Burford, a lawyer and conservative Colorado legislator who was picked by President Ronald Reagan as the first woman to head the Environmental Protection Agency. Her tenure was short and rocky: She clashed with environmentalists and was cited for contempt of Congress in 1982 for refusing to turn over subpoenaed agency documents relating to hazardous waste sites. Although she was following the legal advice of the Justice Department, Burford was forced to resign when the administration gave up the fight. She died in 2004.

After his Supreme Court clerkship, Gorsuch joined the D.C. law firm of Kellogg Huber Hansen Todd Evans & Figel, where he developed a taste for litigation and eventually became a partner. He helped secure what his former partner Hansen said was the largest antitrust award in history and won praise for his courtroom style.

Gorsuch did a short stint as a high-ranking official in the Justice Department and then was nominated to the appeals court by Bush. He sailed through on a voice vote in the full Senate and took his seat on the Denver-based court in August 2006.

Gorsuch is popular with current Supreme Court justices, and his clerks regularly are hired for a term on the high court, not just by conservatives but also by liberals such as Kagan and Justice Sonia Sotomayor.

On the appeals court, Gorsuch has not been called upon to consider two hot-button social issues that may come before the Supreme Court: same-sex marriage and abortion.

After a federal judge in Utah struck down that state’s prohibition on same-sex marriage, Gorsuch was not a member of the 10th Circuit that upheld the decision. It was one of the cases that eventually led to the Supreme Court deciding marriage was a fundamental right that could not be denied gay couples.

Likewise, Gorsuch has not ruled on abortion. But activists on both sides of the issue believe they know where he stands. They point to language in his book “The Future of Assisted Suicide and Euthanasia,” in which he opines that “all human beings are intrinsically valuable and the intentional taking of human life by private persons is always wrong.”

Additionally, his rulings on behalf of those who challenged the Obamacare mandate that employee insurance coverage provide all approved contraceptives seemed instructive. He noted the provision would require the objecting businesses to “underwrite payments for drugs or devices that can have the effect of destroying a fertilized human egg.”

Gorsuch’s opinions favoring the owners of the Hobby Lobby craft stores and a nonprofit religious group called Little Sisters of the Poor took the same sort of broad reading of the Religious Freedom Restoration Act as the Supreme Court’s conservative majority.

In Gorsuch’s words, the law “doesn’t just apply to protect popular religious beliefs: it does perhaps its most important work in protecting unpopular religious beliefs, vindicating this nation’s long-held aspiration to serve as a refuge of religious tolerance.”

Hart, the Democratic law professor, said she resents what Republicans did on the Garland nomination but does not believe there is a “principled reason to block” Gorsuch.

“He will have a strong influence on the court because he’s a very persuasive writer,” she said. “That’s a little scary, but it’s not disqualifying.”

Philip Rucker and Katie Zezima contributed.