Washington (CNN) The Senate confirmed Brett Kavanaugh, 53, to the Supreme Court on Saturday, where he could easily serve for more than two decades and change how the nation's laws are interpreted. He replaces centrist conservative Justice Anthony Kennedy, who retired this summer.

Here's where Kavanaugh, who was a judge on the US Court of Appeals for the DC Circuit for 12 years, stands on some hot-button issues:

Roe v. Wade and abortion rights

During his first round of testimony before the Senate Judiciary Committee, Kavanaugh said he views Roe v. Wade, the landmark ruling that legalized abortion nationwide, as "important precedent of the Supreme Court" that has been "reaffirmed many times." Yet he declined to say he would not vote to reverse Roe, saying that such a vow -- on any case -- would violate judicial norms.

He also defended a dissenting opinion he wrote last year when the full DC Circuit allowed a 17-year-old to end her pregnancy over objections from the Trump administration.

In his dissent , Kavanaugh wrote the Supreme Court has held that "the government has permissible interests in favoring fetal life, protecting the best interests of a minor, and refraining from facilitating abortion." He wrote that the high court has "held that the government may further those interests so long as it does not impose an undue burden on a woman seeking an abortion." He said the majority opinion was "based on a constitutional principle as novel as it is wrong: a new right for unlawful immigrant minors in US government detention to obtain immediate abortion on demand."

JUST WATCHED 2006: Kavanaugh discusses Roe v. Wade Replay More Videos ... MUST WATCH 2006: Kavanaugh discusses Roe v. Wade 00:50

Overall, his testimony reinforced his past writings suggesting he would permit the government to more strictly regulate abortion, for example, with additional requirements that could delay the procedure or stiffer rules for physicians who would perform it.

Trump has long vowed to appoint justices who would reverse Roe and allow the states to determine whether abortion should be legal. Kennedy had been a swing vote in favor of abortion rights.

Executive branch authority

During his confirmation hearings, Kavanaugh declined to elaborate on his views on executive power or protections for a president who might face an investigation and subpoena.

When Democratic Sen. Dianne Feinstein of California asked Kavanaugh if a sitting president could be compelled to respond to a subpoena, he declined to offer his views. "I can't give you an answer on that hypothetical question," he said.

In a 2009 Minnesota Law Review article , Kavanaugh had written that "Congress might consider a law exempting a President -- while in office -- from criminal prosecution and investigation, including from questioning by criminal prosecutors or defense counsel." In the same article, however, he noted, "If the President does something dastardly, the impeachment process is available."

Agency power and government regulation

Kavanaugh has demonstrated a tendency toward suspicion of, rather than deference to, regulatory agency interpretations of federal laws.

"It's all about the statute you write," he emphasized to Sen. Amy Klobuchar, a Minnesota Democrat, noting he would not impose new requirements -- on businesses, for example -- that Congress had not made explicit. That view, as Klobuchar noted, can limit regulatory safeguards on the job, environmental rules and consumer protection.

Kavanaugh's views on government regulation may be best exemplified by his dissent in the case of a killer whale that attacked a SeaWorld trainer.

As Kavanaugh criticized a Labor Department move to sanction SeaWorld following the drowning of a trainer by the orca Tilikum, he declared that the agency had "stormed headlong into a new regulatory arena" and warned that regulators would try to impose new safety requirements on sports, the circus and more.

Overall, his view is that agencies should exercise authority as clearly spelled out in federal statutes and that judges should not, as occurred in the SeaWorld case, defer to agency interpretations that go beyond what's explicit in a law.

In opinions and speeches, Kavanaugh has questioned a ruling in a 1984 Supreme Court case, Chevron v. Natural Resources Defense Council , that said judges should defer to agency interpretations of ambiguous laws. That, he said in a 2017 speech, "encourages agency aggressiveness on a large scale."

Religious liberty

Kavanaugh said generally during his hearings that "it's important to recognize that the First Amendment to the Constitution, as well as many statutes, of course, protect religious liberty in the United States ... and as I've said in some of my opinions, we are all equally American no matter what religion we are or no religion at all -- and that means religious speakers and religious people have a right to their place in the public square."

On the DC Circuit, Kavanaugh dissented in the 2015 case of Priests for Life v. Department of Health and Human Services, focused on a religious exemption to the Affordable Care Act. He dissented when the DC Circuit declined a full court review of a religious group's objection to the process for employers seeking to opt out of the mandate to provide insurance coverage for contraceptives.

Priests for Life had challenged the process for certifying eligibility for exemptions, contending the paperwork involved burdened religious rights. Kavanaugh agreed, saying, "To plaintiffs, the act of submitting this form would, in their religious judgment, impermissibly facilitate delivery of contraceptive and abortifacient coverage."

He said that rather than a form, the group could -- as the Supreme Court had allowed in separate cases -- be permitted to simply notify the secretary of health and human services in writing that it objects to providing coverage for contraceptives.

Second Amendment

In 2011, Kavanaugh dissented from a majority opinion of the DC Circuit that upheld a ban that applied to semiautomatic rifles in the District of Columbia.

In his dissent, he wrote that the Supreme Court had previously "held that handguns -- the vast majority of which today are semiautomatic -- are constitutionally protected because they have not traditionally been banned and are in common use by law-abiding citizens."

Citing a previous high court ruling, Kavanaugh went on to say, "It follows from Heller's protection of semiautomatic handguns that semiautomatic rifles are also constitutionally protected and that DC's ban on them is unconstitutional."

Feinstein pressed Kavanaugh on his dissent during his confirmation hearings, asking, "What did you base your conclusion on that assault weapons are in common use?"

"I had to follow precedent," Kavanaugh said , adding that "semiautomatic rifles are widely possessed in the United States ... so that seemed to fit common use in not being a dangerous and unusual weapon. That was the basis of my dissent."

Privacy and national security

In 2015, Kavanaugh wrote an opinion defending the US government's controversial metadata collection program, in part citing national security considerations. He wrote that the program "is entirely consistent with the Fourth Amendment," which protects against unreasonable search and seizure.

He wrote that the program "does not capture the content of communications, but rather the time and duration of calls and the numbers called," and said it "serves a critically important special need -- preventing terrorist attacks on the United States." Kavanaugh argued "that critical national security need outweighs the impact on privacy occasioned by this program."

Net neutrality

In a 2017 dissent, Kavanaugh said he believed that Obama-era net neutrality regulations were "unlawful" and wrote that the policy violated the First Amendment.

At issue were rules approved by the Federal Communications Commission in 2015 to more strictly regulate the Internet. The rules, based on the principle of "net neutrality," were intended to provide equal opportunity for Internet speeds and access to websites. In a May 2017 order, a majority of the DC Circuit declined to review an earlier decision siding with the FCC. Under the Trump administration, the FCC has since moved to dismantle the regulation.

Kavanaugh wrote in his 2017 dissenting opinion that the regulation was consequential and "transforms the Internet." But he said the rule "impermissibly infringes on the Internet service providers' editorial discretion," and he suggested the FCC had overreached in issuing the regulation. "Congress did not clearly authorize the FCC to issue the net neutrality rule," he wrote.