To President Trump, he’s “a judge’s judge” and “a brilliant legal mind” who deserves swift confirmation.

But to Vanita Gupta, president and chief executive officer of the umbrella Leadership Conference on Civil and Human Rights, new Supreme Court nominee Brett M. Kavanaugh is “a direct threat to our rights and unfit to serve on our nation’s highest court with his record of putting the rich ahead of the rest of us.”

To Sherilyn Ifill, president and director-counsel of the NAACP Legal Defense and Education Fund, the 53-year-old D.C. Circuit Court of Appeals judge would “jeopardize the progress in civil rights law that has been made in the past 78 years by seeking to roll back fair housing laws, affirmative action and a woman’s right to choose.”

And national NAACP President Derrick Johnson declared that the nation’s oldest civil rights group views Judge Kavanaugh as an enemy of “civil rights, workers’ rights, consumer rights and women’s rights.”  

Recalling the NAACP’s opposition to Judge Kavanaugh’s appointment to the appeals court, Mr. Johnson stated that “with a Justice Kavanaugh on the Supreme Court, we could see reversals of hard won gains in equal opportunity in education, employment and housing.

“We could see further exclusion of communities of color from participation in our democracy. We could see racism continue to flourish within the criminal justice system. We could see the elimination of effective tools for proving discrimination.”

All of that makes clear the kind of opposition that Judge Kavanaugh will face as he seeks U.S. Senate confirmation in the coming weeks, with much of the leadership of the African-American and Latino communities seeking to prevent him from being seated on the court.

Senate Republican Leader Mitch McConnell of Kentucky must muster a bare majority of senators to send Judge Kavanaugh to the high court to fill the seat that his mentor and former boss, Justice Anthony M. Kennedy, is leaving.

Judge Kavanaugh started his legal career working as a law clerk for Justice Kennedy, long considered the swing vote on the nine-member court. There are rumors the 81-year-old agreed to retire after receiving assurances his protégé would replace him.

While the civil rights community is rallying against Judge Kavanaugh, Sen. McConnell and other Republican supporters are hailing him as a “superb pick” who could help entrench conservative, corporate-supported control of the law for years to come.

While some Democrats promised to fight to block the nominee, it will be an uphill climb as Republicans control the Senate by a 51-49 margin, though that margin is slimmer with GOP Sen. John McCain absent in Arizona battling brain cancer.

Judge Kavanaugh, who would follow Justice Neil Gorsuch as a Trump pick on the court, is a well-known figure in Washington and has been involved in some of the biggest controversies of the past two decades.

He helped investigate former Democratic President Bill Clinton in the 1990s working for independent counsel Kenneth Starr.

He also was on Republican George W. Bush’s team in the contentious Florida recount fight in the 2000 presidential election, then served as a senior official in Bush’s White House.

Judge Kavanaugh would not immediately change the ideological breakdown of a court that already has a 5-4 conservative majority, but nevertheless could move the court to the right. Justice Kennedy sometimes joined the liberal justices on key rulings on such social issues like abortion and gay rights, a practice his replacement may not duplicate.

Judge Kavanaugh has amassed a solidly conservative judicial record since 2006 with the 300 opinions he has written since joining the D.C. court, the same court on which three current justices previously served, including Chief Justice John Roberts.

“My judicial philosophy is straightforward: A judge must be independent and must interpret the law, not make the law,” Judge Kavanaugh said after accepting the nomination Monday at the White House.

“A judge must interpret statutes as written. And a judge must interpret the Constitution as written, informed by history and tradition and precedent,” he said in remarks in which he also talked about his family and emphasized his Roman Catholic faith.

Judge Kavanaugh survived a three-year confirmation fight to get on the appeals court.

Opponents are hoping Republican Sens. Susan Collins of Maine and Lisa Murkowski of Alaska will help block his confirmation. Sens. Collins and Murkowski support abortion rights and plan to carefully vet Judge Kavanaugh’s views on women’s rights.

Meanwhile, Republicans are hoping for votes of support from several Democratic senators facing re-election this year in Republican-leaning states, including Sens. Joe Manchin of West Virginia, Joe Donnelly of Indiana and Heidi Heitkamp of North Dakota.

The new justice can be expected to cast crucial votes on matters of national importance including gay rights, gun control, the death penalty and voting rights.

The court could also be called upon to render judgment on issues of personal significance to President Trump and his administration, including matters arising from Special Counsel Robert Mueller’s ongoing Russia-related investigation and several civil lawsuits pending against President Trump.

People are now combing through his opinions, which have a consistent business-first, citizens-last ring, according to legal scholars.

For example, Judge Kavanaugh faulted Obama-era environmental regulations, including upholding a coal company’s challenge to emissions policies aimed at fighting climate change.

In 2016, he wrote the appeals court decision that found unconstitutional the structure of the Consumer Financial Protection Bureau, which was formed under President Obama to stop banks and other powerful corporations from gouging ordinary people.

In 2011, he dissented as the court upheld a District of Columbia gun law that banned semi-automatic rifles, opining that such weapons of war are open to citizen ownership under the U.S. Constitution’s Second Amendment

Last October, he was part of a panel of judges that issued an order preventing a 17-year-old undocumented immigrant detained in Texas by U.S. authorities from immediately obtaining an abortion. That decision was overturned by the full appeals court, and she had the abortion.

Judge Kavanaugh wrote in a dissent that the full court was embracing “a new right for unlawful immigrant minors in U.S. government detention to obtain immediate abortion on demand.”

He also dissented in 2015 when the appeals court spurned religious groups that sought an exemption from a requirement under the 2010 Obamacare healthcare law that employers provide health insurance that covers birth control for women.

Judge Kavanaugh grew up in Bethesda, Md., and attended the same high school as Justice Gorsuch. Both men served as clerks in the Supreme Court’s 1993-1994 term to Justice Kennedy, who announced his retirement on June 27.

A graduate of Yale Law School, Judge Kavanaugh may have helped save President Obama’s health care law by mentioning in a dissent that the requirement to buy health insurance seemed like a tax, an idea that the Chief Justice Roberts picked up in upholding the Affordable Care Act in 2012.

In his remarks on Monday, Judge Kavanaugh sought to spotlight his bipartisan credentials. He noted that he has taught at Harvard Law School, where he was hired by Justice Elena Kagan, a former Harvard dean who is now on the U.S. Supreme Court. He said a majority of his clerks have been women.

He worked for four years for Mr. Starr, whose investigation of President Clinton helped spur an effort by congressional Republicans in 1998 and 1999 to impeach the Democratic president and remove him from office.

In 2009, Judge Kavanaugh wrote a law review article questioning the value of that investigation and concluding that presidents should be free from the distractions of civil lawsuits, criminal prosecutions and investigations while in office.

That view has assumed fresh relevance, with President Trump facing several civil lawsuits as well as a Russia-related criminal investigation by Mr. Mueller. The Supreme Court could be called upon to weigh in on these matters.