Ray Locker

USA TODAY

The comparisons between President Richard Nixon, the Watergate scandal that helped end his presidency and President Trump are coming with an increasing frequency these days, particularly after Trump's firing of FBI Director James Comey Tuesday.

Watergate refers to the all-encompassing series of scandals that engulfed Nixon starting with the June 17, 1972, failed break-in at the Democratic National Committee headquarters in Washington's Watergate office complex. Five men, including four Cuban exiles affiliated with the CIA and James McCord, the security director of Nixon's 1972 re-election committee, were caught inside the DNC offices with bugging equipment and photographs.

By the time Nixon resigned and left office on Aug. 9, 1974, the scandal had become a catalog of many of Nixon's abuses of power. They included FBI wiretaps of 17 government officials and journalists, a 1970 plan to relax internal security procedures to track suspected subversives, the existence of a secret White House special investigations unit called the Plumbers, the secret bombing of Cambodia and a wide-ranging dirty tricks program run by the Nixon 1972 campaign team against potential Democratic opponents.

The final straw was the release of June 23, 1972, tape of a conversation between Nixon and his chief of staff, H.R. Haldeman, in which Nixon approved a plan to use the CIA to block the FBI's investigation of the Watergate break-in.

The Trump campaign and some of his associates are being investigated by the FBI and two congressional committees for possible involvement in the Russian-led hacking of the Democratic National Committee's email system and the transfer of those emails to the online site WikiLeaks, which posts secret government and political documents online. Nothing so far links Trump personally to the hacking or leaks.

So, what are the similarities and differences between the Trump White House and Nixon's?

Similarities

• Firing investigators. By May 1973, a special prosecutor was appointed by Attorney General Elliot Richardson to investigate potential crimes stemming from the Watergate break-in and subsequent White House cover-up of its involvement. Richardson, a former secretary of Defense and Health, Education and Welfare, appointed his former mentor from Harvard Law School, Archibald Cox. A former solicitor general for President John Kennedy, a Nixon nemesis, Cox quickly angered the Nixon White House with his demands for documents and tapes of Nixon's conversations in the White House, the existence of which was revealed in July.

On Oct. 20, 1973, Nixon ordered Richardson to fire Cox. Richardson refused and resigned. Nixon then asked Richardson's deputy, William Ruckelshaus, to fire Cox, He, too, refused and resigned. Solicitor General Robert Bork, the No. 3 official in the Justice Department, agreed to fire Cox, reasoning that Nixon would just roll through the entire department until he found someone willing to get rid of Cox. Those firings, called the Saturday Night Massacre, increased calls for Nixon's impeachment.

On Monday, Trump fired FBI Director James Comey, saying that he had lost confidence in Comey's ability to run the FBI because of how he handled last year's investigation into Hillary Clinton's use of a private email server on which some classified government documents were sent. Comey's firing spurred immediate comparisons to the Cox firing, because the FBI is also investigating connections between Trump's campaign and administration with Russia and its interference in the 2016 elections.

• Embattled White House spokesmen. Nixon's press secretary, Ronald Ziegler, became notorious for his briefings in which he tried to explain the continually changing explanations from the White House about the involvement of administration officials in the Watergate break-in and cover-up. During one briefing, Ziegler said his previous, inaccurate statements were "inoperative."

Sean Spicer, Trump's press secretary, has struggled to deal with the president's numerous tweets and inaccurate statements. On Tuesday, he reportedly told television camera operators to turn off their lights as he and other members of the White House press team tried to explain the Comey firing.

• Campaign dirty tricks. Nixon's campaign hired young political operatives to disrupt the operations of several Democratic candidates for president in 1972. They included, as the Washington Post wrote on Oct. 10, 1972, "Following members of Democratic candidates' families and assembling dossiers on their personal lives; forging letters and distributing them under the candidates' letterheads; leaking false and manufactured items to the press; throwing campaign schedules into disarray; seizing confidential campaign files; and investigating the lives of dozens of Democratic campaign workers."

The Trump campaign benefited from a Russian plan to destabilize the U.S. elections last year, which included the hacking of Democratic National Committee emails by a hacker called Guccifer 2.0. Those emails were then given to the online leak site WikiLeaks and distributed over a period of weeks during the height of the general election campaign. Roger Stone, an alumnus of the 1972 Nixon campaign and a longtime Trump adviser, spoke often during the campaign of impending WikiLeaks email dumps and their effect on the campaign of Democratic nominee Clinton.

In each case, it was never proved that Nixon knew in advance about his campaign's dirty tricks or that Trump had any knowledge of the connections of people affiliated with his campaign with the Russian government or its agents.

Differences

• There is no special prosecutor. Yet. Nixon was forced to agree to the appointment of Cox and his successor, high-powered Houston lawyer Leon Jaworski to lead a special prosecution team of Watergate-related crimes because of charges that the Justice Department was too politically compromised to investigate the president who had appointed its top officers.

Claims of political bias exist now, but so far neither Trump, Attorney General Jeff Sessions or key Republicans, such as Senate Majority Leader Mitch McConnell, have endorsed calling for a special prosecutor into the Russia hacking case. Sessions has recused himself from any role in the Russia investigation, citing his contacts with Russian Ambassador Sergey Kislyak, which Sessions failed to acknowledge during his Senate confirmation hearings. Any special prosecutor in that case would have to be appointed by Deputy Attorney General Rod Rosenstein, but he and Sessions both were involved in the firing of FBI director Comey.

• Congressional control. In 1973, Congress was controlled by Democrats, who had long distrusted Republican Nixon for a series of political maneuvers over the course of his political career, which started in 1946. Senate Democrats called for the creation of a special committee, the Senate Select Committee on Presidential Campaign Activities, to investigate the claims of dirty tricks and the White House connection to the Watergate break-in. After the Saturday Night Massacre, calls for impeachment proceedings for Nixon picked up steam. By the summer of 1974, the House Judiciary Committee was considering multiple articles of impeachment against Nixon.

This year, however, the White House and Congress are controlled by Republicans, and congressional leadership has been quiet in calling for a special prosecutor or a deeper investigation into the Trump administration. However, the GOP-controlled Senate and House intelligence committees are investigating the Trump campaign and the Russian hacking. The Senate investigation, led by Sen. Richard Burr, R-N.C., has been noted for its cooperation with Senate Democrats, particularly Sen. Mark Warner of Virginia, while the House probe has been stalled by political squabbling and the recusal of the panel's chairman, Rep. Devin Nunes of California, for his meetings with Trump officials.

Where to learn more

Historians and journalists have covered the Nixon administration and Watergate in great detail. Here are some books that explain more about what happened and what more parallels may exist between the Nixon and Trump administrations.

The Wars of Watergate: The Last Crisis of Richard Nixon, by Stanley Kutler.

Silent Coup: The Removal of a President, by Len Colodny and Robert Gettlin.

Nightmare: The Underside of the Nixon Years, by J. Anthony Lukas.

Richard Nixon: The Life, by John A. Farrell.

Being Nixon: A Man Divided, by Evan Thomas.

The Strong Man: John Mitchell and the Secrets of Watergate, by James Rosen.

The Nixon Tapes, 1971-1972. by Douglas Brinkley & Luke Nichter.

The Nixon Tapes: 1973, by Douglas Brinkley & Luke Nichter.

The Final Days, by Bob Woodward and Carl Bernstein.

Read more:

CIA director misled FBI about how agency spied on Pentagon Papers leaker

New bio: Why Richard Nixon matters in the Trump era