WASHINGTON - Brett Kavanaugh, President Donald Trump's second Supreme Court nominee in two years, was officially sworn in on Saturday, shortly after the Senate narrowly confirmed him by a vote of 50 to 48 amid fierce partisan fights focusing on sexual misconduct allegations against him.

The 53-year-old conservative was sworn in as 114th Supreme Court justice by Chief Justice John Roberts Jr. and retired Justice Anthony Kennedy in a private ceremony at the Supreme Court.

Kavanaugh succeeded 82-year-old Justice Kennedy who has been a moderate and pivotal swing vote between conservatives and liberals on the nine-member bench for years.

As a result, Kavanaugh's lifetime appointment appeared to secure a solid majority of conservatives on the US highest court for years, a big win for Trump and the Republican Party.

Kavanaugh has served as a judge of the US Court of Appeals for the District of Columbia Circuit since 2006. Prior to that, he served in the George W. Bush administration, as an associate counsel and then subsequently as assistant to the president and staff secretary.

A graduate of Yale College and Yale Law School, Kavanaugh clerked in the Supreme Court for Justice Kennedy and for judges of circuit courts of appeals. He also served as a counsel for the Office of Independent Counsel under Ken Starr and as a partner at Kirkland & Ellis, LLP.

Amid partisan fights over the confirmation, three women came forward last month to accuse Kavanaugh of sexually assaulting or harassing them during his high school and university years. Kavanaugh has denied all the accusations.

The nine-member Supreme Court decides matters that shape the country's politics. It is both the highest appeals panel and a constitutional court.

Trump nominated Neil Gorsuch, seen as solidly conservative, to the court shortly after he took office in January 2017. Gorsuch was confirmed by the Senate with a 54-45 vote months later.