Dear Congressional Republicans,

As you spend time with your families over the recess, I suggest that you might invest a few hours reflecting on the Nixon era in Washington.

Yes, the parallels to Watergate are sometimes used like a cudgel by liberal columnists and pundits. And, of course, Memorial Day is the proper time to honor those who served in Vietnam, especially the more than 58,000 names etched on the Wall in Washington.

But my point is different from standard commentary on MSNBC and patriotic speeches about those who died in combat.

For Republicans in Congress or the administration during the early 1970s, many of the fiercest battles were waged in private over family dinner tables or when sons and daughters came home from college. In that tumultuous era, supporting a lawless president and a no-exit war often led to deep and lasting rifts with children and spouses.

What also should be apparent is the enduring cultural fascination with Watergate, which predates Donald Trump’s presidency. Even as we near the 46th anniversary of the June 17, 1972, break-in at the Democratic National Committee, the events that led to Richard Nixon’s downfall seem vivid and contemporary in a way that the Iran-Contra scandal and Bill Clinton’s impeachment do not.

[The Watergate Hearings: 45 Years Later]

I am stressing this history because there will be a time of reckoning for current Republicans in Congress over their conduct and complicity during the Trump era. It may not come this November or even in 2020. But as long as fidelity to democratic norms and the rule of law remain American virtues, such a day of judgment is inevitable.

Just consider the events of the last few days. On Sunday, Trump, in a dramatic break with legal precedent, demanded that the Justice Department open up an investigation into the FBI’s 2016 probe of Russian influence on his presidential campaign.

The outcry from Democrats, former Justice Department officials and constitutional scholars was immediate. The silence from Republicans on Capitol Hill was deafening.

Watch: Schumer Says White House’s Inquiries About Mueller Investigation Are ‘Unprecedented’

In a White House meeting with Trump on Monday, Deputy Attorney General Rod Rosenstein and FBI Director Christopher Wray offered a series of murky concessions, including expanding an existing investigation by the Justice Department’s inspector general into FBI tactics regarding Trump during the 2016 campaign.

The sudden flexibility by Rosenstein and Wray may reflect their awareness that Republicans of all stripes on Capitol Hill went AWOL during the latest challenge to the independence of the Russia investigation. Without congressional backing, Rosenstein and Wray may have felt they had no option but to play for time.

No one with an IQ greater than a dead flashlight battery seriously believes that the FBI’s use of an informant to talk to peripheral Trump 2016 campaign officials like Carter Page and George Papadopoulos had much of a bearing on anything.

Instead, the most serious and devastating FBI intervention into the 2016 campaign came when James Comey publicly announced the reopening of the Hillary Clinton email investigation 11 days before the election. As Comey has admitted during his book tour, the FBI director made the fateful decision at a time when he was certain that Clinton would be the 45th president.

But Hillary the Victim has gotten lost in Trump’s bellowing about a purported scandal bigger than Watergate. In truth, public reticence by Comey and other FBI officials protected the Trump campaign from any 2016 airing of its many ties to Russian meddling.

At this point, you may be asking, “What does any of this have to do with me as a Republican in Congress?”

Imagine the year is 2033 and your favorite grandchild is eager to discuss your role during the Trump tumult. What would you say to him or her about your silence as the president bluntly intervened in a valid Justice Department investigation of his own campaign?

“I wasn’t on the Judiciary or the Intelligence committees, so it really wasn’t my business to get involved.”

“I waited for Mitch McConnell or Paul Ryan to say something. And when they didn’t, I decided that party loyalty was the safest course.”

“While I didn’t have a serious current primary opponent, I didn’t want to do anything that would put me in jeopardy in 2020.”

“Think what it would have done to my family and my political career if Trump had attacked me in a tweet.”

“The Democrats would have done the same thing if they had the power. Just remember Hillary and Benghazi.”

“The only things that mattered to me in the Senate were tax cuts and getting conservative judges into the courts.”

“I only watched Fox News, so I didn’t realize that Trump had crossed a line.”

“I was holding my fire in case Trump fired Robert Mueller.”

Added together, these excuses have all the credibility of Alfred E. Neuman declaring, “What, me worry?” on the cover of a 1970s Mad magazine. Do you really think that your grandchildren will be impressed by your craven explanations for your silence?

An enduring truth about public service is that legislators do not get unlimited chances to do the right thing. Eventually, you are judged by your public conduct rather than private good intentions to someday maybe protect Mueller.

Donald Trump’s contempt for the traditions of democracy and legal precedents might have been expected from watching his campaign. What is surprising and dispiriting is the lapdog fidelity of Republicans in Congress.

Make no mistake, my friends. There will be a day of judgment.  

Walter Shapiro, a Roll Call columnist since 2015, has covered the last 10 presidential campaigns. He is also a fellow at the Brennan Center for Justice at NYU and a lecturer in political science at Yale. Follow him on Twitter @MrWalterShapiro.