By Susan Cornwell
WASHINGTON, Feb 9 (Reuters) - When former President Donald Trump's second impeachment trial opens on Tuesday, presiding over it will not be U.S. Chief Justice John Roberts, who oversaw Trump's first trial, but a Democratic senator who will also get a say in the verdict.
Patrick Leahy of Vermont is president pro tempore of the Senate, meaning he is empowered to preside over Senate sessions in the absence of Vice President Kamala Harris.
The Constitution requires the Supreme Court chief to preside in presidential impeachments. When Leahy, who at age 80 is the longest-serving member of the Senate, disclosed last month he would fill that role in Trump's trial, he noted the president pro tempore had historically presided over Senate impeachment trials of non-presidents. Trump left the White House last month after his Nov. 3 election defeat by now-President Joe Biden.
Leahy, a liberal lawmaker, has vowed to be fair, but some Republicans and Trump's lawyers have criticized the arrangement.
"Now, instead of the Chief Justice, the trial will be overseen by a biased and partisan Senator who will purportedly also act as a juror while ruling on issues that arise during trial," Trump's lawyers wrote in a legal brief filed on Monday.
They suggested Leahy's role would be grounds for a court challenge of any conviction.
The criticism belies the fact that a member of the Senate presides at most sessions of the body, including on sensitive votes, in a procedure accepted by both parties.
The House of Representatives voted last month to impeach Trump, accusing him of inciting insurrection in a fiery speech to his followers before a deadly Jan. 6 attack on the Capitol.
The day after he announced his presiding role last month, Leahy briefly visited a Washington hospital. The next day, he was back at work, and told reporters he had experienced "muscle spasms."
But the health scare highlighted the Democrats' precarious hold on the chamber. The Senate is divided 50-50 along party lines, and Democrats have the majority only through Harris' tie-breaking vote.
(Reporting by Susan Cornwell; Editing by Scott Malone and Peter Cooney)
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