The Senate Judiciary Committee has scheduled an extraordinary and likely decisive hearing Thursday on President Trump’s nomination of Judge Brett M. Kavanaugh to be the Supreme Court’s 114th justice.

The senators will consider decades-old sexual misconduct allegations leveled at Kavanaugh since the committee earlier held four days of hearings on the judge’s nomination.

Who is Brett Kavanaugh?

Kavanaugh, 53, is a rarity for the Supreme Court: He was born in Washington, grew up in the Maryland suburbs and has lived his adult life in the area. He went to Georgetown Preparatory School and resides with his wife and two daughters in Chevy Chase.

His undergraduate and law degrees are from Yale, the school where Justices Clarence Thomas, Samuel A. Alito Jr. and Sonia Sotomayor also earned law degrees.

For the Supreme Court term that began in 1993, he was a clerk for Justice Anthony M. Kennedy, the man he would replace. Justice Neil M. Gorsuch, Trump’s first Supreme Court nominee, also worked in Kennedy’s chambers that term.

The vast majority of Kavanaugh’s professional life has been in government jobs rather than private practice. He served for four years as an assistant to independent counsel Kenneth W. Starr in the investigations of the Clinton administration and the suicide of Clinton aide Vince Foster.

He served five years in the administration of President George W. Bush, first as an associate counsel and then as staff secretary. Bush nominated Kavanaugh to the U.S. Court of Appeals for the D.C. Circuit. After a bitter nomination fight that lasted years, Kavanaugh was confirmed in 2006. He has been part of more than 300 opinions on that court, with a consistently conservative record.

What are his confirmation chances?

Before allegations of sexual misconduct as a teenager, they were very good.

The confirmation process is tilted in favor of the nominee when the White House and Senate are controlled by the same political party.

When Democrats last controlled the Senate, they changed the judicial nomination process to dispose of a requirement for a supermajority vote to proceed on the nomination of a lower-court judge. Senate Majority Leader Mitch McConnell (R-Ky.) pushed through a change in 2017 to include Supreme Court nominees, to move forward the nomination of Gorsuch.

Republicans have a slim majority in the chamber. For Kavanaugh, that means he will be confirmed if all GOP senators support him, regardless of Democratic opposition. No Republicans have announced opposition, and several Democrats said they are keeping an open mind. Several voted for Gorsuch.

What are the allegations?

Christine Blasey Ford alleges that sometime in 1982, at a friend’s house, Kavanaugh pinned her on a bed, drunkenly groped her, tried to take off her clothes and put his hand over her mouth when she tried to scream. Ford said a friend of Kavanaugh, Mark Judge, was in the room — but neither Judge nor others who she said were in the house at the time have claimed any knowledge or memory of the incident.

After Ford’s allegations surfaced, New Yorker magazine reported that Deborah Ramirez, a classmate of Kavanaugh’s at Yale, said he exposed himself at a party when they were both first-year students.

Ramirez, who told the magazine that they both had been drinking at the time of the incident, acknowledged gaps in her memory but said she remembered Kavanaugh pulling up his pants and another student shouting Kavanaugh’s name.

In an appearance with his wife, Ashley, on a Fox News show Monday, Kavanaugh repeated his denial that either event took place.

“The truth is I’ve never sexually assaulted anyone, in high school or otherwise,” he said.

Who opposes his confirmation?

Most Democratic senators oppose Kavanaugh. Besides the allegations, Democrats have complained that Kavanaugh is too conservative and would push the court too far to the right, especially on issues such as abortion, voting rights, affirmative action, the environment and gay rights.

And so it follows that the loudest objections to Kavanaugh come from liberal organizations and groups dedicated to those issues. Because of the potential Kavanaugh holds to move the court to the right, some abortion rights groups and environmental organizations that in the past have remained neutral on Supreme Court nominees have opposed Kavanaugh.

How could the court change?

Kavanaugh’s is the rare Supreme Court nomination that could dramatically alter the court.

Usually a president is replacing one liberal with another, or one conservative with someone else on the right. Both of President Barack Obama’s nominations fit that pattern, for instance, as did Trump’s choice of Gorsuch to take the place of Justice Antonin Scalia after his death.

But Kavanaugh would be replacing a pivotal justice, one who most of the time voted with fellow conservatives but sided with liberals on some of the most important decisions the court made on social issues.

Kavanaugh’s confirmation would probably mean that Chief Justice John G. Roberts Jr. would become the court’s justice-in-the-middle. That is an unusual role for a chief justice. He has formed a majority with liberals in only a handful of cases.

In the court’s most recent decisions on affirmative action, abortion and gay rights, for instance, Kennedy provided the deciding vote and Roberts sided with conservatives in the minority.

Does this mean abortion will be outlawed?

Not necessarily. But it would indicate that more of the restrictions on the procedure that some states have enacted would be approved by the Supreme Court.

Kennedy was part of the majority that in a 1992 case, Planned Parenthood v. Casey, upheld the basic guarantee of Roe v. Wade that a woman has a right to obtain an abortion. While the decision acknowledged a state’s interest in protecting fetal life, it said restrictions could not impose an “undue burden” on a woman’s right.

The fight since then has been over where to draw that line.

It’s possible that a court without Kennedy would overturn Casey and, by extension, Roe. But it could also whittle away at the right by approving more restrictions.

In the court’s most recent look at abortion rights, Kennedy sided with the court’s liberals in striking down a Texas law that imposed additional requirements of doctors and clinics. The majority said they were pretext for restricting access.

Trump said during the campaign he would nominate only “pro-life judges,” and it is likely that Gorsuch and Kavanaugh, if they had been on the court at the time, would have sided with the other conservatives to uphold the law.

There are numerous challenges to abortion restrictions imposed by states on their way to the Supreme Court.

Will the health-care law be overturned?

That is certainly one reason Democrats give for opposing Kavanaugh’s nomination. Another challenge to the Affordable Care Act has been filed by states that say recent action by Congress has undermined the legal argument the Supreme Court used to uphold the law.

Kavanaugh may be amenable to such an argument, but this is one area where his replacement of Kennedy does not necessarily shift the court.

Kennedy was in the minority when Roberts joined the court’s liberals to uphold the health-care law on a 5-to-4 vote in 2010. The five justices that made up the majority are still on the court. Kennedy did vote with them in a second challenge to the ACA, but his sixth vote was unnecessary to the outcome.