The internal White House debate over who should replace Justice Anthony Kennedy on the Supreme Court reflects the broader political split within the Republican Party — and the mistrust that is nursed by outside-the-Beltway social conservatives about the more establishment and business-oriented wing of the party.

So it is perhaps no surprise that a quintessentially Washingtonian fight has erupted between the supporters of the two leading candidates for the nomination, Judge Brett Kavanaugh and Judge Amy Coney Barrett.

It's like a color war in camp. A prominent legal conservative of the behind-the-scene battle over Judges Kavanaugh and Barrett

While Barrett's supporters portray Kavanaugh as insufficiently conservative, Kavanaugh's supporters portray Barrett as insufficiently experienced — a judge whose conservative credentials are not yet clear in her opinions.

In truth, both are very conservative legal believers who would undoubtedly push the Supreme Court far to the right of where it was during Kennedy's more centrist conservative time on the Supreme Court.

Barrett has a long paper trail of academic writing in the law, but Kavanaugh has a long paper trail of actual legal opinions. Both have written things that Democrats could use against them at confirmation hearings. But what is interesting to watch is two factions of Republicans, behind the scenes, battling each other, leaking unflattering and even false things about either Kavanaugh or Barrett.

Social conservatives seem to have coalesced behind Judge Amy Coney Barrett, who spent much of her career as a law professor at Notre Dame. (University of Notre Dame Law School via AP)

Social conservatives seem to have coalesced behind Barrett, who spent much of her career as a law professor at Notre Dame. She is a mother of seven children, two of them adopted from Haiti, and she is an active member of a particularly conservative Catholic religious group called People of Praise.

Although there were rumors that her interview with President Trump did not go well last week, sources tell NPR that is not true and that the president wants to appoint her to the Supreme Court, but is concerned about her lack of a record on the bench.

Within the White House, those in charge of the selection process, especially counsel Don McGahn, want a no-sweat redo of the process that produced the president's 2017 Supreme Court pick, Justice Neil Gorsuch.

Trump essentially outsourced much of that selection process to the conservative Federalist Society. The result was that while the White House was in chaos in the early months of the administration, the Gorsuch selection went smoothly, as did a confirmation process that included getting rid of the century-old filibuster rule in the Senate that would have required a 60-vote majority to win confirmation.

While social conservatives have repeatedly thanked Trump for the Gorsuch nomination, they seem to want more. In an open letter last week, leaders of the American Family Association, the American Principles Project and other socially conservative groups urged the appointment of Barrett.

"It is better to have a vacancy until next year than to fill the seat with a weak nominee who will betray your legacy and the constitution for the next 40 years," they wrote.

Why the strong preference for Barrett over Kavanaugh? As one prominent legal conservative put it, "It's like a color war in camp." Each side just distrusts the other.

One suspects that, in the end, the president will go for the safest choice, the choice that will cause the least trouble and result in a relatively quick confirmation process. That would be Kavanaugh.

While nobody is saying that the president has finally made up his mind, those opposed to Kavanaugh are running out of time to gin up a real opposition within the conservative movement.

Of course, there is always the possibility that knocking out Kavanaugh would not mean knocking in Barrett. It might also mean that another one of the below judges gets the nod, including Judge Raymond Kethledge of the 6th Circuit Court of Appeals in Michigan. The president met with Kethledge and reportedly got along with him.

Still in the mix, too, is Judge Thomas Hardiman of Pennsylvania, the runner-up from the last go-round, when Gorsuch was elevated instead.

Less likely, but also still a consideration, is Amul Thapar of Kentucky. Thapar is the preferred judge of Mitch McConnell, the Kentucky senator and Senate majority leader, who controls the confirmation process and timing in the U.S. Senate.

Here's a look at the pros, cons and records of each of the candidates on the shortlist:

Brett Kavanaugh of Maryland, U.S. Court of Appeals for the District of Columbia Circuit

Kavanaugh, 53, is a former clerk to the man he could replace on the Supreme Court, Kennedy. He was named to the D.C. Circuit by George W. Bush in 2003, but his confirmation was stalled by Democrats for nearly three years. They said he was too partisan, young and inexperienced.

They also said he was too partisan because of his work for independent counsel Kenneth Starr in the investigation of President Bill Clinton, his involvement in the Florida recount in 2000, and his work as a counsel and later staff secretary for Bush, during which he took strong positions in favor of presidential power and privilege. In 2006, he was finally confirmed.

Kavanaugh's record on the D.C. Circuit Court of Appeals, with some 286-plus opinions, is definitely the most prolific of any of the potential nominees. It is a record noteworthy for its skill and conservatism.

In a recent case that combined the controversial issues of abortion and immigration, he wrote a decision that temporarily barred a pregnant teenager, who was in immigration custody, from obtaining an abortion. The decision, for a three-judge court, was subsequently overturned by the full court, over Kavanaugh's dissent.

He also dissented in a case involving a challenge brought by religious groups to the contraception provision of the Affordable Care Act. That regulation required religious groups to certify that they were exempting themselves from providing contraceptive services; it was eventually withdrawn by the Trump administration.

On questions involving government regulation, he often, but not always, has sought to limit or throw out Obama-era environmental regulations.

Kavanaugh has also authored or signed on to a number of opinions deferring to presidential power in high-profile cases. For instance, after the Supreme Court ruled that enemy combatants detained at Guantanamo Bay have the right to challenge their detentions in court, Kavanaugh was among the conservative judges on the D.C. Circuit who subsequently ruled in ways that critics have said actively subverted the high court's decision, so as to render it toothless.

Finally, Kavanaugh wrote an extensive law review article in 2009 that could have implications for the special counsel investigation into Russian interference in the 2016 election. In that article, he said that after seeing firsthand the many difficult duties that a president encounters, he thinks, in retrospect, that presidents should operate free from the threat of civil suits — like the sexual harassment suit that led to Clinton's impeachment — and that presidents should also be free from criminal investigations.

The article seems to suggest that both of these presidential protections should be enacted by Congress but does not say do without qualification. Such views could well have implications for special counsel Robert Mueller's investigation of Trump, including the question of whether the president can be subpoenaed to answer questions about his possible involvement in criminal activity. The ultimate check on a president's criminal actions, Kavanaugh said, is impeachment, but he does not say how members of Congress might gather the needed information for such a proceeding.

Amy Coney Barrett of Indiana, U.S. Court of Appeals for the 7th Circuit

Barrett, 46, a former University of Notre Dame law professor, was nominated to the appeals court by Trump and confirmed by the Senate in October 2017. She was a law clerk for Supreme Court Justice Antonin Scalia.

At Barrett's confirmation hearing, some Democrats questioned whether her Catholic beliefs, which they characterized as religious "dogma," would influence her legal decisions, a suggestion that outraged many of her defenders, both Catholic and non-Catholic alike.

In her academic writing, she has written somewhat dismissively of the doctrine of respecting the Supreme Court's precedents — a doctrine known as stare decisis. "There is little reason to think that reversals [of past decisions] would do much damage" to the court's reputation, she wrote. "I tend to agree with those who say that a justice's duty is to the Constitution" rather than to a precedent she thinks is clearly in conflict with it.

Such comments are likely to raise a red flag to Republican senators like Susan Collins of Maine, who have said they would not vote for a nominee who has expressed doubts about stare decisis when it comes to abortion and other long-standing Supreme Court decisions.

Raymond Kethledge of Michigan, U.S. Court of Appeals for the 6th Circuit

Kethledge, another former Kennedy law clerk, has been identified as the third top contender for the open court seat. First nominated to the 6th Circuit by George W. Bush in 2006, his nomination stalled because of opposition from Michigan's two Democratic senators.

Among all the reported short-listers, Raymond Kethledge of the 6th U.S. Circuit Court of Appeals is the only non-Catholic. (Image from video provided by C-SPAN via AP)

Bush renominated Kethledge in 2007, and he was finally approved by the Senate in 2008. He is 51, and among all the reported short-listers, he is the only non-Catholic. He is an evangelical Christian whose book Lead Yourself First uses President Dwight Eisenhower, primatologist Jane Goodall, Winston Churchill, Martin Luther King Jr. and others as examples of "leaders who have used solitude to function more effectively."

Among Kethledge's notable rulings is a 2016 decision in favor of a group called NorCal Tea Party Patriots, condemning the IRS for appearing to target conservative groups by slowing down their applications for tax-exempt status.

Sure to be controversial is a 2017 decision involving the alleged targeting of Hispanics for questioning by Border Patrol agents. In that decision, Kethledge accepted the assertions of Border Patrol agents that in using the terms "wets" and "tonks," they were referring to undocumented persons generally and not to Hispanics specifically.

And in a rape case, Kethledge dissented. He would have allowed the trial court to hear evidence of the accuser's sexual history with the defendant. In another criminal case, he wrote that police do not have to obtain a search warrant to obtain a suspect's cellphone location information. That decision was reversed by the U.S. Supreme Court this year in a landmark ruling.

Thomas Hardiman of Pennsylvania, U.S. Court of Appeals for the 3rd Circuit

Judge Thomas Hardiman was the runner-up to Neil Gorsuch for the Supreme Court vacancy last year. (Matt Slocum/AP)

The 52-year-old Hardiman was nominated to the federal trial court by George W. Bush in 2003 and to the 3rd Circuit in 2007 and was confirmed by the Senate in a 95-0 vote.

He was the runner-up to succeed Scalia on the Supreme Court, the seat Gorsuch was eventually tapped to fill. Trump is said to have particularly liked Hardiman's life story. He was the first in his family to go to college, at the University of Notre Dame, then worked as a taxi driver to finance his legal education at Georgetown Law School.

More than the other potential nominees, Hardiman has a strong record in favor of gun rights. When the court he serves on upheld a New Jersey law requiring a gun owner to obtain a permit to carry a gun in public places and to show that he has "a justifiable need" to carry the gun, Hardiman dissented, chastising the majority for upholding a law that dates to 1966 (and arguably 1924) as insufficiently long-standing.

In 2017, when Hardiman was last considered for a Supreme Court seat, he had the support of the president's sister, Maryanne Trump Barry. Barry served alongside Hardiman as a federal appeals judge on the 3rd Circuit before stepping down last year.

Amul Thapar of Kentucky, U.S. Court of Appeals for the 6th Circuit

Judge Amul Thapar is a personal favorite of Senate Republican leader Mitch McConnell of Kentucky. (Ed Reinke/AP)

The son of Indian immigrants, Thapar, age 49, has had a meteoric rise. Originally from Michigan, he is a personal favorite of Senate Republican leader McConnell of Kentucky, who in 2006 handpicked him to be one of two U.S. attorneys in the state. A year later, Thapar was nominated to the federal trial court by President George W. Bush and confirmed unanimously.

He was the first federal court judge of South Asian descent. In 2017, Trump nominated Thapar to the 6th Circuit Court of Appeals, which covers much of the Midwest.

The Louisville Courier-Journal reported that Thapar's father, Raj Thapar, who owns a heating and air-conditioning supply business in Toledo, Ohio, says his son is "so conservative that he 'nearly wouldn't speak to me after I voted for Barack Obama.' "

Most of Thapar's judicial record stems from his tenure as a federal district judge. However, a significant part of his record would seem to reflect his tenure as a federal prosecutor in Cincinnati; Washington, D.C.; and ultimately as the chief federal prosecutor in the Eastern District of Kentucky.

One high-profile case involved three members of the Christian pacifist group Plowshares, including a nun in her 80s, who were convicted of invading a federal nuclear plant in Oak Ridge, Tenn., splattering blood and writing anti-war messages on the wall. They were convicted of a variety of charges, including sabotage.

Thapar denied their motion for a judgment of acquittal on the sabotage charge, saying the Constitution leaves the judgment of whether it makes "sense to deal as harshly with non-violent protesters as with foreign saboteurs ... to the policymaking branches."

He then sentenced two of the protesters to five years in prison, and the 84-year-old nun, Sister Megan-Rice, to a 35-month term. The sabotage conviction was later overturned by the 6th Circuit Court of Appeals, in an opinion written by another Trump potential nominee, Kethledge.

NPR's Domenico Montanaro contributed to this report.

Correction: July 6, 2018 12:00 am — A previous version of this story incorrectly said two of Judge Amy Coney Barrett's children were adopted from Haiti after the 2010 earthquake. One of her sons was adopted after the earthquake, but the daughter who was born in Haiti was adopted earlier. In addition, the story also said Judge Brett Kavanaugh wrote an article in 2013 about presidential protection from lawsuits and criminal investigation. The article was published in 2009.

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