Former FBI Director James Comey will testify Thursday before the Senate Intelligence Committee — his first public statement since President Donald Trump abruptly fired him last month.

Comey's ouster has prompted more than a few comparisons between the ongoing Russia-related investigations and the Watergate scandal of the 1970s.

Both situations involve a break-in of the Democratic National Committee, the firing of top government investigators, and accusations that the president obstructed justice.

Comey's testimony wouldn't be the first time a leader of the FBI provided evidence of presidential impropriety — the deputy director of the FBI during the Nixon administration, Mark Felt, turned out to be "Deep Throat," the key anonymous source in the reporting that cracked open Watergate.

Last month, reports emerged that Trump had asked Comey, who was leading the top law-enforcement agency's investigation into whether Trump campaign officials colluded with the Russian government to influence the 2016 election, to drop an investigation into Trump's former national security adviser, Michael Flynn.

Since those reports — and others saying Trump asked top intelligence officials to publicly deny that any collusion had occurred — comparisons between Watergate and the scandal consuming the current White House have become increasingly common.

Richard Nixon. Getty Images And while it could be months before FBI investigators determine whether any wrongdoing occurred, Julian Zelizer, a professor of history and public affairs at Princeton University, says Watergate can teach us a lot about the current moment.

Zelizer says that, as became true in Watergate, the most important question right now may not concern the ongoing investigations, but how the president has reacted to them — a question Comey is likely to address in his testimony.

"The original investigation of the original crime is often less important than how the president responds to that," Zelizer told Business Insider. "Does he abuse his power? Does he try to obstruct? How does he handle the scandal?"

Congress never determined whether Nixon himself ordered the 1972 break-in — he was forced to resign after it was revealed that he attempted to obstruct justice and cover up the crime.

Comey's testimony, Zelizer says, is likely to reveal little or nothing about the FBI's investigation, but focus on whether Trump acted improperly in his response to the probe.

"The big question is how much does he talk about not necessarily his conclusion that the president obstructed justice, but, certainly, fears that the president's being improper," Zelizer said. "If he's willing to say that, I think that's enough for Congress to really accelerate this investigation."

In his prepared written testimony, which the Senate Intelligence Committee released on Wednesday, Comey called Trump's behavior "inappropriate" — a term open to interpretation and something lawmakers are likely to press him to clarify.

But Morton Keller, a professor emeritus of history at Brandeis University, said comparisons to Watergate were presumptuous.

"In my youth, there was an expression 'If my grandmother had wheels, she'd be a trolley car,'" Keller told Business Insider. "If this has wheels, it may be another Watergate. But so far, I don't see the wheels."

He added that the lesson to take from Watergate was that "if there's smoke, there may be fire, but you got to find the fire first."

But Zelizer says that regardless of whether a crime is ever uncovered, the nation is in a similar position today as it was 44 years ago.

"It's more than fair to say that we're certainly at the place that we were with Watergate in 1973, where there were a lot of red flags and enough for Congress, for journalists, for citizens to be seriously concerned," Zelizer said.

What the 1970s can teach us

Congressional testimony can provide many pivotal moments in a scandal. It certainly did during the Watergate investigation.

In a week of testimony before the Senate's Watergate committee, Nixon's White House counsel, John Dean, was first to describe a complex and far-reaching secret intelligence-gathering operation that involved the president. He famously recalled a conversation in which he said he told Nixon there was a "cancer growing on the presidency and that if the cancer was not removed, the president himself would be killed by it."

A month later, Alexander Butterfield, Nixon's deputy chief of staff, told the committee that Nixon did, in fact, have "listening devices" in the Oval Office. On those tapes, which the Supreme Court ultimately ruled must be released, Nixon was recorded discussing the cover-up of a break-in into the DNC headquarters in Washington, DC.

But politics are decidedly different in 2017 than they were in 1973. Congress is deeply divided along partisan lines, and Republicans hold majorities in the House and Senate. Democrats controlled both congressional bodies while the Watergate investigation was underway.

Zelizer said the kinds of questions Comey faces tomorrow might signal how willing Republicans are to hold their party accountable.

"Can the Republican Congress conduct an investigation and ask Comey the kinds of questions that the Congress of '73 was able to ask of Nixon administration officials, including Republicans?" he said.