(CNN) - As special counsel Robert Mueller prepares a final report on his investigation of Russia's interference in the 2016 election and possible Trump campaign complicity, two historic presidential inquiries offer distinct -- and clashing -- models.
In 1974, when special prosecutor Leon Jaworski delivered a report related to President Richard Nixon's cover-up of the Watergate burglary, it was a tightly written 55-page catalogue of evidence. It contained no moral judgments and made clear that action against the President rested with Congress.
In 1998, after independent counsel Ken Starr finished a investigation of President Bill Clinton, his report was more than 400 pages, including a salacious narrative of the President's sexual relationship with former White House intern Monica Lewinsky. It contained 11 possible grounds for impeachment, beginning with the assertion that Clinton lied under oath.
The key Jaworski document delivered to the House of Representatives was kept under seal for more than four decades, released only last October. The Starr report became public immediately, distributed on the Internet and shocking the public with its voluminous details about Clinton's dalliances with Lewinsky.
Nixon resigned before he could be impeached. Clinton was impeached but acquitted by the Senate.
Today, as Mueller reportedly nears the end of the Russia probe tracing to 2016, these two historic episodes suggest possible approaches for a final report but also point to differences for the current multi-year probe hanging over the Trump presidency.
Unlike with the work of Jaworski and Starr, Mueller is operating under a statute that requires he submit a confidential report directly to the attorney general, who has discretion on how to handle it. William Barr, likely to be confirmed as attorney general shortly, has not pledged to make the full report public. And it is unclear what information will be transmitted to Congress.
Justice Department guidelines say a sitting president cannot be criminally indicted; it would be up to the House to act on possible allegations of obstruction of justice or other wrongdoing. If it were to impeach the President, a trial would be held in the Senate.
Jaworski's 'road map'
The Nixon and Clinton investigations differed significantly from the outset. The former began with the June 1972 break-in of the Democratic National Committee headquarters at the Watergate office building.
At the time that Jaworski delivered his March 1974 report, he had already brought multiple criminal cases against officials who conspired in the burglary and its cover-up. His office had obtained several guilty pleas and indictments were pending against Nixon officials in the highest echelons, including former Attorney General John Mitchell. Jaworski was about to seek a subpoena for Nixon's Oval Office tapes, and the House Judiciary Committee had already begun the impeachment process.
The Jaworski "road map," as it became known, helped steer the Democratic-led House as it prepared articles of impeachment, spurring Nixon's resignation on August 9, 1974.
In Jaworski's resignation letter to then-Attorney General William Saxbe in October 1974, he briefly observed, "While the grand jury report, which presented the chain of evidence in detail, has not been published, I am informed that it served as a major guide for the staff and members of the Committee in the development of ... the Articles of Impeachment."
That report was made public last October, through a lawsuit brought by Protect Democracy, on behalf of Harvard Law Professor Jack Goldsmith, LawFare editor in chief Benjamin Wittes, and Stephen Bates, currently a professor at the University of Nevada, Las Vegas, who in the 1990s was part of the Starr legal team.
In a LawFare piece last October, Goldsmith and Wittes praised the Jaworski document for its brevity and neutral, non-prosecutorial tone.
"It does not argue that Nixon committed any impeachable offense," they wrote. "It simply makes a series of factual claims, each written in a spare and clinical fashion, each supported by citations to material the special prosecutor's office provided to Congress."
Goldsmith and Wittes said that for Mueller one lesson would be: Less is more.
"The document is powerful because it is so spare; because it is trying to inform, not to persuade; because it utterly lacks rhetorical excess," they wrote. "Starr took a different path."
The Starr report
The Starr report, which was also prepared by now-Supreme Court Justice Brett Kavanaugh, was intensely prosecutorial and spared little in terms of sexual descriptions of the Clinton and Lewinsky liaisons.
Bates, who defends the Starr report, agrees however with Goldsmith and Wittes about the value of a special counsel stressing the role of Congress in deciding a president's fate. In an interview on Saturday he also emphasized the differences at the Capitol during the Nixon and Clinton episodes.
Unlike in 1974, when the House Judiciary Committee was already pursing Watergate, he said the House in 1998 was essentially waiting for the Starr report.
"Whatever the Starr office was going to send to the Hill, it was going to be more detailed than the Jaworski report," Bates said.
Once the Starr report was in hand, House Republicans initiated impeachment proceedings. Clinton was impeached for perjury and obstruction of justice. The Senate acquitted Clinton and he served out his full second term as president.
Of Mueller, Bates predicted a fuller analysis than Jaworski's, simply because the Russia investigation appears far more complicated.
Added Bates, "The world is just waiting for Mueller now."