Washington (CNN) Known for his golden resume and powers of persuasion, John Roberts was named chief justice of the United States at the age of 50. In the 15 years since, he's hewed to his conservative roots but moved warily on some cases to shield the reputation of the Supreme Court.

But that often happens behind the scenes and at a court where no cameras are allowed. Now Roberts will be in the national spotlight as never before, presiding over the Senate trial of President Donald Trump before an audience of millions.

Roberts, who turns 65 later this month, has played multiple roles in Washington but kept the same face: reserved, practiced, steady. Since he was a prep school student in northern Indiana and through his early years at Harvard, he has striven to be top-notch. He oversees a conservative majority on a tightly divided Supreme Court, yet he constantly touts the impartiality of the federal judiciary. He has sparred publicly with Trump on that score.

Roberts is also a devotee of Bob Dylan , an avid reader of history, and the father of two children, etched in a public tableau from his 2005 confirmation, who will turn 20 this year. He and his wife, Jane, a lawyer and legal recruiter, spend their summers on an island in Maine, a fitting refuge for a man who holds the nation's highest judicial post and covets a low personal profile.

As much as Roberts publicly rejects the politics of Washington, as the top judicial figure in the nation he cannot escape it. In 2012, he negotiated to save the Barack Obama-sponsored Affordable Care Act, but more in keeping with his conservative record, he has limited the reach of Voting Rights Act's protections, curbed campaign-finance regulations and closed the doors of federal courthouses to lawsuits over intense partisan gerrymanders.

The highly visible venue of the impeachment trial will challenge Roberts, whose work across the street from the Capitol at the marble-columned court proceeds in a camera-free zone , mainly in closed chambers.

Roberts is also keenly aware that his bench -- five Republican-nominated conservatives and four Democratic-nominated liberals -- faces criticism for deciding cases in favor of political conservatives. As he undertakes a role that is distinctly separate from his leadership at the high court, he will try to preserve the integrity of the court and his own reputation.

He will likely try to avoid appearing a pawn of the Senate Republican majority or, alternatively, the sudden savior to House Democrats pressing their case against Trump. It is an uphill climb for the House, not merely because of fights over whether witnesses will be called, but because a conviction would require a two-thirds vote of senators.

Never in American history has the Senate met the threshold to remove a president from office.

'I've always wanted to stay ahead of the crowd'

Roberts was born in Buffalo, New York, and grew up in northern Indiana, where his father was an executive at Bethlehem Steel. A new boarding school had opened a few years before he was finishing eighth grade, and as a 13-year-old he wrote a letter to the La Lumiere headmaster seeking admission to the high school.

"I've always wanted to stay ahead of the crowd," Roberts wrote, adding. "I won't be content to get a good job by getting a good education, I want to get the best job by getting the best education."

Roberts was such a serious child that an aunt said he was sometimes known, fondly, as "sober puss."

He was accepted to the La Lumiere school, graduated first in his class, sped through Harvard College in three years and entered Harvard Law School, where he was managing editor of the law review. After his 1979 graduation, Roberts earned two prestigious judicial clerkships, for Judge Henry Friendly, on the New York-based 2nd Circuit, and for then-Associate Justice William Rehnquist.

Rehnquist, who was elevated to chief justice in 1986, presided over the impeachment trial of President Bill Clinton in 1999, and will be a model for Roberts.

Roberts worked in Republican President Ronald Reagan's Justice Department, first with Ken Starr, the attorney general's chief of staff, and then in the White House counsel's office, under Fred Fielding. Roberts was a loyal soldier in the Reagan conservative social agenda, against affirmative action and other racial remedies and in favor of school prayer and religious displays.

He later described hearing a "call to action" from Reagan. "I felt he was speaking directly to me."

In the George H.W. Bush administration, Roberts was a deputy solicitor general, chosen again by Starr, who was then US Solicitor General and who later as an independent counsel investigated President Clinton and steered that impeachment.

Roberts, in his role as deputy solicitor general and in private practice, argued 39 cases before the Supreme Court.

"No one presented better arguments on a more consistent basis," retired Justice Sandra Day O'Connor once wrote of Roberts' style as an appellate advocate standing before the nine justices.

During the 2000 presidential election ordeal, he joined fellow conservatives from the Reagan-Bush years to help former Texas Gov. George W. Bush, son of the first President Bush, claim the disputed Florida electoral votes.

That same year of the Supreme Court's Bush v. Gore case, Roberts and his wife adopted two infant children, separated in age by about five months. Adoption had been a long-held hope of the couple who had married in 1996, both 41 years old at the time, and Jane has spoken openly about the adoptions in the years since.

The children were in the public eye after the new President Bush nominated Roberts to the DC Circuit in 2001 (Roberts was confirmed in 2003) and then in 2005 when Bush elevated Roberts to the Supreme Court.

During the latter episode, as Bush was announcing Roberts' name on national television, 4 ½ year old Jack broke away from his mother and began dancing, just out of sight of the cameras airing the live event. "We later learned he was imitating Spider-Man," Bush wrote in his 2010 memoir. "I saw him out of the corner of my eye, and it took all my concentration to continue my remarks."

Roberts himself said in a 2006 speech, "It was, in retrospect, endearing. I assure you, only in retrospect."

Federal appeals court judge John G. Roberts Jr.'s (L) son John (3rd R) dances as US President George W. Bush (C) announces Roberts as his first Supreme Court nominee during a prime-time speech 18 July 2005 from the White House in Washington as Roberts wife Jane (2nd R), duaghter Josephine (R) look on.

At that July White House announcement, Roberts had been nominated for an associate justice post, to succeed the retiring Justice Sandra Day O'Connor. Bush selected him over other "short list" candidates who had more judicial experience.

"I believed Roberts would be a natural leader," Bush later wrote. "I didn't worry about him drifting away from his principles over time." Roberts' famed metaphor of judge-as-umpire, merely "calling balls and strikes," also resonated with Bush.

Within weeks of that nomination, a series of events propelled Roberts to the top spot.

Before the Senate could hold its confirmation hearings, Chief Justice Rehnquist, battling thyroid cancer, died. That September 3 death occurred in the middle of Hurricane Katrina tragedy, when the Category 5 storm overwhelmed New Orleans levees and flooded the city. More than a thousand people died. Bush was under intense criticism because of the federal government's bungled response. People were stranded, dead bodies were left in the streets.

Hearing of Rehnquist's death, Bush immediately decided to elevate Roberts, who had received initial praise from senators, and wait to fill the O'Connor position. At age 50, Roberts would be the youngest chief justice in more than two centuries.

During his Senate confirmation hearing, Roberts skillfully parried questions and was confirmed 78-22. Tapes of his hearings have since been circulated among judicial nominees as a model. With a smooth manner and a dry wit, Robert expressed general principles, avoiding any legal stand.

Sen. Chuck Schumer, now the Senate's top Democrat and then a member of the Senate Judiciary Committee, complained to the nominee about his evasive answers.

"It's as if I asked you: 'What kind of movies do you like? Tell me two or three good movies. And you say, 'I like movies with good acting. I like movies with good directing. I like movies with good cinematography.' And I ask you, 'No, give me an example of a good movie.' You don't name one."

The committee chairman cut off Schumer. Roberts, however, decided to jump in: "I'll be very succinct. First 'Doctor Zhivago' and 'North by Northwest.'"

"Now, how about the more important subject..." Schumer began, but the chairman said Schumer was out of time.

Roberts's active role leading the court

In the past two years, since the retirement of centrist conservative Justice Anthony Kennedy, Roberts has crept ever so slightly to the center on the sharply divided bench, perhaps to prevent more 5-4 ideological outcomes.

For years, his surprise move to uphold Obamacare stood out. The chief switched his vote to save the law, over the howls of Republicans, including Trump, who blasted Roberts both at the time and during the 2016 presidential election.

Last June, after another behind-the-scenes negotiation, Roberts joined with the four liberal justices to block the addition of a citizenship question on the 2020 census.

Still, Roberts has remained largely nestled on the right-wing and, in a signature set of cases, has been consistent on fighting the use of affirmative action and racial remedies. "It is a sordid business, this divvying us up by race," he wrote in a 2006 voting rights case. The following year, as he rejected school integration plans in Louisville and Seattle, he wrote, "The way to stop discrimination on the basis of race is to stop discriminating on the basis of race."

Roberts believes that the government remedies tied to race are counterproductive and outdated. He made that clear as he has narrowly interpreted the landmark 1965 Voting Rights Act.

Roberts wrote the majority opinion in the 2013 Shelby County v. Holder striking down a provision that required certain states and localities, mainly in the South, to obtain federal approval before instituting new election rules.

"Our country has changed," he said, rejecting the provision tied to a 1960s formula, "and while any racial discrimination in voting is too much, Congress must ensure that the legislation it passes to remedy that problem speaks to current conditions."

Justice Ruth Bader Ginsburg took the lead in a dissent, writing an opinion that first gave rise to the "Notorious RBG" meme on social media.

"The sad irony of today's decision lies in its utter failure to grasp why the VRA has proven effective," she wrote, adding that "throwing out preclearance when it has worked and is continuing to work to stop discriminatory changes is like throwing away your umbrella in a rainstorm because you are not getting wet."

Roberts' dissents on the high court have been rare but often notable, such as on same-sex marriage.

The chief justice dissented in 2015 when Kennedy joined the four liberals to declare a right to same-sex marriage. He compared the court's decision to the infamous Dred Scott v. Sandford that said blacks could not be citizens, as he asserted that the current majority had preempted the political process in the states and undermined the constitutional order.

"Just who do we think we are?" Roberts asked, adding that the justices form a court, not a legislature.

When Kennedy, who wrote the majority opinion in Obergefell v. Hodges , retired in 2018, Roberts moved to the center of the ideological spectrum. That was simply by virtue of Kennedy's replacement, Brett Kavanaugh, who holds a more conservative record. But Roberts is unlikely to offer a variable vote in the mode of Kennedy. Roberts has simply laid down more conservative markers over the years.

Yet, Roberts is concerned about the court's reputation in polarized Washington. In 2018, when the President derided a federal judge who had ruled against his administration as "an Obama judge," Roberts issued a statement that said, "We do not have Obama judges or Trump judges, Bush judges or Clinton judges. What we have is an extraordinary group of dedicated judges doing their level best to do equal right to those appearing before them."

Roberts is also mindful of his own institutional reputation. Before he turned to law at Harvard, Roberts considered getting a PhD in history and he has remained a student of history, especially judicial history.

As he mulled the reputations of past chief justices, he said at one public appearance, "You wonder if you're going to be John Marshall or you're going to be Roger Taney," referring to the nation's great chief justice and the author of Dred Scott. "The answer is, of course, you are certainly not going to be John Marshall. But you want to avoid the danger of being Roger Taney."