New York(ANN)-US Chief Justice John Roberts will be a central figure in the ongoing drama of the Donald Trump presidency in coming months.

He is due to preside over a Senate impeachment trial, while the Supreme Court he leads will rule on a titanic clash over the president’s attempts to keep his financial records secret.

The expected impeachment trial will focus on accusations that Trump abused his power by asking Ukraine to investigate former Democratic Vice President Joe Biden, who aspires to defeat Trump in a November election.

The Democratic-led House of Representatives approved two articles of impeachment on Dec. 18, paving the way for the trial in the Senate, led by Trump’s fellow Republicans.

The normally reserved and mild-mannered Roberts, 64, will have the largely symbolic role of presiding officer, with senators casting the crucial votes.

In his end-of-year message on Tuesday, Roberts hinted at a past disagreement with Trump, saying an independent judiciary was a “key source of national unity and stability,” and called on his judicial colleagues to promote public confidence and trust by reflecting on their duty to judge without fear or favor.

Trump has repeatedly criticized federal courts and judges who have blocked his policies, while some Democratic lawmakers have suggested that the Supreme Court’s conservative majority is motivated mainly by politics instead of interpreting the law.

In his message Roberts also cautioned against disinformation amplified by the internet and social media – an accusation that Trump has faced when he uses his Twitter account to retweet unfounded rumor.

It is in the marble-lined corridors of the Supreme Court across the street from the Capitol Building, hidden from the TV cameras, where Roberts wields real power.

Known for his cautious approach to major cases, he holds one of just nine votes that will decide by the end of June whether Trump’s financial records can be disclosed to Democratic-led congressional committees and a New York prosecutor.

The court’s rulings in those cases – on the power of Congress and local prosecutors to investigate a sitting president – will set precedents that may affect not just Trump but also future presidents.

The impeachment trial will be an unusual and potentially uncomfortable period for the low-key Roberts, who prefers to fly under the radar even while he has navigated the conservative-majority court in a rightward direction over the last decade and a half.

“My sense is that the chief doesn’t want to make himself the story,” said Sarah Binder, a scholar at the nonpartisan Brookings Institution. Roberts declined to comment.

During a rare public appearance in New York in September, Roberts appeared concerned about the hyperpartisan politics of Washington under Trump.

“When you live in a polarized political environment, people tend to see everything in those terms. That’s not how we at the court function,” he said.

Those who know Roberts, including former law clerks, say that he would take his role seriously. As a history buff, he is likely reading up on the previous impeachment trials of Presidents Andrew Johnson and Bill Clinton, they said.

(Source: Reuters)