Now, as President Donald Trump continues to hold up Kavanaugh as a political trophy, the new Supreme Court justice himself is trying to lower his profile.
Kavanaugh also seems inclined against a prominent role at next week's annual meeting of the Federalist Society, the group working with the White House to confirm conservative judges, to which Justice Neil Gorsuch, Trump's first appointee, gave a rousing keynote speech last year.
Within the court, Kavanaugh has deferred to his colleagues in oral arguments and quickly adhered to the court's institutional traditions. The other justices have gone out of their way to be publicly welcoming and have shown an unusual degree of collegiality all around during arguments so far this term, even laughing more at one another's jokes.
All told, Kavanaugh appears to be lying low after the volatile confirmation process and buttressing Roberts' efforts to move the court away from the white-hot media spotlight.
Yet Kavanaugh, a political insider who spent 12 years on a US appeals court, also understands that the media scrutiny will fade. The record of Kavanaugh, 53 and appointed for life, will become clear only over many months and years.
For the law in America, the newest of the nine represents only part of a momentous change underway. For years as the justices met privately to decide cases in a rich oak-paneled conference room, the person whose views mattered most was Justice Anthony Kennedy, whom Kavanaugh succeeded.
A conservative with centrist tendencies on social issues -- including abortion, race and gay rights -- Kennedy was regularly the deciding vote. Like the lawyers who stood at the lectern and publicly argued before the high court, individual justices often tailored their arguments around the private conference table to Kennedy.
Not one of the current nine has a similar centrist approach. Justices on both sides of the ideological divide are watching Kavanaugh for any clues about how to best approach the new justice.
Kavanaugh was carefully vetted by a Trump team that did not want a vacillating jurist in the mode of Kennedy.
Kavanaugh's style is different and he appears to be trying to make good on his oft-repeated confirmation mantra about "always being a team player on the team of nine."
Where Gorsuch immediately opted against having his clerks join the clerk pool that collectively screens petitions for certiorari, seeking review of cases lost in lower courts, Kavanaugh has had his clerks join. (All justices but Gorsuch and Samuel Alito are in the so-called cert pool, which dates to the 1970s.)
In the private conference, the junior justice has the responsibility of taking notes on the proceedings and answering the door if any aide knocks to offer a document or even a fetched set of forgotten reading glasses or a coffee cup requested by a justice.
That person is now Kavanaugh. He will also be last in line to cast his vote. In tight cases, he likely would be the fifth conservative, sealing a victory for the right wing. Or he may prove unpredictable, perhaps even defying his benefactor.
Before this week's midterm elections, as Trump tried to rally Republicans, he constantly invoked Kavanaugh's appointment and the Democratic opposition he faced. The day after the election, the President boasted that the Kavanaugh strategy paid off.
"By expanding our Senate majority, the voters have also clearly rebuked the Senate Democrats for their handling of the Kavanaugh hearings," Trump said at a White House news conference.
"Tremendous energy was given to the Republican Party by the way they treated then-Judge Kavanaugh, now Justice Kavanaugh," he said.
Kavanaugh's response to the sexual assault allegations of Christine Blasey Ford prompted some lawyers and judges, including retired Justice John Paul Stevens, to question his temperament and ability to be an impartial jurist.
During the Senate hearing, Kavanaugh described Ford's claims as part of "a calculated and orchestrated political hit, fueled with apparent pent-up anger about President Trump and the 2016 election ... revenge on behalf of the Clintons and millions of dollars in money from outside left-wing opposition groups."
Individual justices are conflicted over how Kavanaugh's confirmation unfolded, yet all have an incentive to be collegial and forward-looking. They have projected a "business as usual" image, even appearing to be getting along better on the bench.
Kavanaugh has now sat through three weeks of oral arguments. He has held back and let his colleagues air their queries before jumping in. He also has tried to take opportunities to question both sides in fractious cases, perhaps to avoid being labeled with a predictably conservative approach.
Fellow justices have shown regard for his questioning, occasionally picking up on his line of inquiry.
"What the treaty seems to prevent," Justice Elena Kagan observed to a lawyer at the lectern in one case, "is the state from taking either travel or, as Justice Kavanaugh says, travel with goods."
At another point, Kagan, who sits next to Kavanaugh on the bench, said, "I think the import of Justice Kavanaugh's question is that in the usual case. ... "
In a separate dispute, after Kavanaugh had tried to enter the fray but was interrupted, Roberts stopped the lawyer at the lectern. "I think Justice Kavanaugh had a question," Roberts said, ensuring Kavanaugh an opening.
Later in the same argument, Kavanaugh said, "to pick up on the chief justice's comments. ... "
While they are united in public, with Kennedy's departure the court is more divided on the substance of the law, split between five conservatives (Roberts, Kavanaugh, Gorsuch, Alito and Clarence Thomas) and four liberals (Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor and Kagan).
Yet the chief justice has been determined to show that the court is above politics. Roberts may end up inching to the left himself in some cases, to avoid some 5-4 splits, and may find a new ally in Kavanaugh.
How those justices on the right band together -- or not -- could make a difference in the cases the court takes up and the fate of long-standing precedents, for example on abortion rights. Where Kavanaugh falls on the ideological spectrum could also affect larger constitutional dilemmas, provoked by Trump's demonstrated disregard for legal norms.
Kavanaugh and Roberts, a decade older at 63, have known each other for nearly 30 years. Both served in the US Solicitor General's Office during the George H.W. Bush administration, Roberts as a deputy SG and Kavanaugh on a fellowship for young lawyers. During the George W. Bush administration, Kavanaugh obtained top legal jobs and Roberts won court appointments, first to the US Court of Appeals for the District of Columbia Circuit, in 2003, and then to the Supreme Court, in 2005.
Kavanaugh himself then served on the DC Circuit, reinforcing their common path. They have long had a friendly relationship.
Last month, when Kavanaugh underwent a ceremonial investiture at the White House, following his 50-48 confirmation vote by the Senate, he went out of his way to praise Roberts.
"Chief Justice Roberts is a principled, independent and inspiring leader for the American judiciary," Kavanaugh said. "As a country, we are fortunate to have John Roberts as chief justice of the United States."
Roberts returned the favorable comments when he spoke of judicial independence, after referring to "the contentious events in Washington," at the University of Minnesota the following week.
"As our newest colleague put it, we do not sit on opposite sides of an aisle, we do not caucus in separate rooms, we do not serve one party or one interest. We serve one nation," Roberts said.
The 2018-19 session, which began a week before Kavanaugh was seated last month, is still so new that he and most justices have yet to issue any written opinions. But Kavanaugh has taken actions that separate him from the conservative stalwarts.
In late October, when the court took up a challenge to the Commerce Department's addition of a citizenship question on the 2020 census, Kavanaugh was with the majority in allowing lower court proceedings to continue and testimony to be taken from a key Justice Department lawyer in the dispute, while his fellow conservatives Gorsuch and Thomas dissented. (Separately, the full court blocked the challengers from obtaining testimony from Commerce Secretary Wilbur Ross.)
In none of those three matters did Kavanaugh write anything that became public.
Trump had no public comment on any of them, either. The President still speaks enthusiastically of his new nominee and suggests he believes the high court will be more on his side.
"We want to be in the Supreme Court on DACA," Trump told reporters Friday morning, later adding, "where we'll be given a fair decision."
And earlier in the week, before Tuesday's elections, the President raised Kavanaugh's name to rally campaign crowds. He cast Kavanaugh as a victim of false accusers and their Democratic enablers.
"False accusations. False accusations," Trump said. "They want to ruin a man or a woman. Ruin a man."