Lurking behind the polished decorum and hushed solemnity of the opening yesterday of this century's first presidential impeachment trial were the ignoble shadows of 1868.
President Andrew Johnson narrowly escaped conviction by the Senate in May that year, but not before opponents castigated him as "scurrilous" and a "trickster" during a stridently partisan trial.
Will the Senate trial of President Clinton sink into the same bitter partisanship that marked Johnson's ordeal and also characterized last month's party-line impeachment proceedings in the House of Representatives?
Will members of the elite chamber - empowered with the sole authority to remove the president from office - hew closely to established legal standards of fairness, or veer off on an uncharted, politically driven course?
Finally, will an anticipated full Senate trial - possibly including witnesses - offer the president a reasonable opportunity to defend himself against charges that he committed perjury and obstructed justice?
Unlike the House, the Senate has three essential constitutional safeguards designed to prevent a trial replete with partisan rancor: first, an impartial presiding judge - in this case Supreme Court Chief Justice William Rehnquist. Second, a sworn oath that binds each of the 100 senators to "do impartial justice." Last and most important, a two-thirds majority vote to convict the president.
Yet these broad constraints failed to stop senators in 1868 from staging a passionately politicized trial. Indeed, each individual senator today - as well as the 55-strong Republican majority - holds significant powers to shape the direction and tone of the proceedings. Senators are free at any time to introduce motions, and with simple majority votes they can override Justice Rehnquist's rulings or even the Senate's own 26 rules for impeachment trials.
As senators continue behind-the-scenes maneuvering to forge a trial plan for next week, experts differ over whether they will heed accepted trial standards, or risk infusing the process with politics by making up new rules as they go along - acting as if "bound by no law," as one House prosecutor back in 1868 asserted they could.
The partisanship genie
As the trial opened yesterday in a volatile atmosphere, some senators and experts voiced concern about a quick descent into partisanship.
"I worry that a small group of extreme people can control the process and roll it out of control," said Sen. Charles Schumer (D) of New York in a television interview, expressing the fears of several Senate Democrats.
"It could become a series of party-line votes," agreed Georgetown University law professor Susan Low Bloch. "I hope we won't see that, but nothing would prevent it except on the ultimate question [of conviction]."
Others, however, predicted that the constitutional safeguards will provide for greater fairness.
The Senate trial will be a "more complete and fair proceeding for the president" than in the House, says Michael Gerhardt, an impeachment expert at the College of William and Mary in Williamsburg, Va. "[Senators] understand that you will not get a super-majority vote through sheer partisanship." Instead, he says, the two-thirds vote required to convict "forces people to look beyond party identification to find grounds for agreement."
As a result, "the chance of this deteriorating into a partisan brawl is remote," said Sen. Mitch McConnell (R) of Kentucky, a view echoed by other Republicans.
In addition, some experts believe the sheer weightiness of the trial proceedings, as well as the fact that the public is watching on television, may create "a culture ... that will possibly tamp down partisan inclinations," says George Washington University law professor Mary Cheh.
A better forum for Clinton
Overall, most observers say Mr. Clinton's defense team will have a greater opportunity than it did in the House to tell the president's side of the story.
Nevertheless, the team of 13 House "managers," or prosecutors, led by Illinois Republican Rep. Henry Hyde, is also likely to mount a vigorous case. The prosecutorial team, composed of some of the House's most outspoken proponents of impeachment, will "press this case zealously," says Buckner Melton, a professor at the University of North Carolina at Chapel Hill.
Presiding over the House managers and Clinton's lawyers, the Supreme Court's Rehnquist could serve as a moderating influence, says Ms. Cheh. "It would take a pretty strong momentum for senators to be in any continual way interrupting the proceedings," she says.
But it remains uncertain how much authority the senators, who are empowered to act both as judge and jury, will abrogate to Rehnquist. Even a precedent that would allow Rehnquist to cast a tie-breaking vote may not stand, says Mr. Gerhardt. "The jurors are driving the process."
Indeed, the senators hold virtually all the trump cards in deciding how this trial plays out - and they can set their own standards. Specifically, they can decide with a simple majority vote whether to call witnesses and what evidentiary rules apply, such as whether evidence is considered relevant, hearsay, or inflammatory. Each senator also decides individually what burden of proof to apply, such as "clear and convincing evidence," "beyond a reasonable doubt," or a standard of their own choosing.