The most successful intervention in modern political history took place a half-century ago on Aug. 7, 1974.

After the Supreme Court ordered the release of the Watergate “smoking gun” tape, three leading congressional Republicans made a lonely pilgrimage to the White House to brief Richard Nixon on his dire prospects. 

Sen. Barry Goldwater, the GOP’s ill-fated 1964 nominee, took the lead and bluntly told the president that he had maybe 18 votes at best against removal from office after a Senate trial. Goldwater hinted that he himself was wavering. 

Little more than 24 hours later in an evening television address, Nixon — a president known for his resilience and his survival skills — announced that he was resigning the presidency. 

As skittish and panicked Democrats return to the Capitol with Joe Biden’s candidacy teetering on the ropes, it is easy to conjure up 1974 as a parallel. The week will be filled with formal and informal — secret and not so secret — meetings and meals dominated by one topic: “What to do about Joe?”

But there is an important difference: Nixon’s fate was completely up to the Congress. The self-interest of Senate and House Democrats is, in some way, independent of Biden’s bleak reelection prospects. 

Polling analyst Nate Silver, in a New York Times op-ed last week, pointed out that Democratic Senate candidates in rough races are running better than Biden in 46 of the 47 quality surveys. In fact, based on this premature polling, they’re on target to survive the drag at the top of the ticket. 

At this stage in the political cycle, there are almost no reliable House polls. But it is easy to imagine that House Democrats, facing difficult races in November, will pivot to arguing that blocking a GOP takeover of Congress is the only way to resist the excesses of a Donald Trump vengeance-is-mine second term. 

Little that Biden has done since the most disastrous debate in American history should reassure anyone who wants to defeat Trump in November. 

Yes, the president was fierce in an 18-minute call into MSNBC’s “Morning Joe” on Monday as he denounced “the elites in the party — Oh, they know so much more.” But it is a strange position when an incumbent president suddenly announces he’s the Great Outsider. 

A single phone-in does not erase a shaky TV interview with ABC’s George Stephanopoulos in which the president wish-cast his troubling polling away. Nor has there been anything inspiring about Biden’s often brief public appearances chained to his teleprompter.

While Biden, with his more than three decades in the Senate, is particularly sensitive to the vibes from Capitol Hill, Democratic legislators should not be the major pressure group pushing for political realism from the beleaguered president.  

An intervention is needed from Biden’s excessively loyal advisers in the White House who see the president every day — and almost certainly have sensed the deterioration. Instead, these aides appear to be encouraging the worst aspects of Biden’s bunker mentality. 

Biden’s Monday letter to Democrats in Congress was a prime example of the power of arrogance. Chortling over his 14 million votes in the Democratic primaries — with no real opposition and scant public awareness of the president’s limitations for a grueling campaign — is unconvincing given the changed circumstances. 

Biden continued in this “the debate never happened mode” when he argued in the letter that the decision about a 2024 nominee was up to the voters — and “not the press, not the pundits, not the big donors, and not any selected group of individuals.” 

Political parties have mechanisms to replace candidates because circumstances change. 

A Wall Street Journal poll after the debate found that 80 percent of voters believe that Biden is too old to run for a second term. How do the president and his enablers spin their way out of that one?

Biden has not yet been nominated — and the hope remains, after the current show of defiance, that the president will release his delegates before the Chicago convention. 

While Biden was in the Senate, the Democrats endured three successive presidential wipeouts in the 1980s. 

I vividly recall the miasma of defeat that hung over the 1984 Democratic convention in San Francisco in a race in which Walter Mondale lost 49 states. The Atlanta convention that nominated Michael Dukakis in 1988 wasn’t much better. That was a year when the Republicans under George H.W. Bush carried California, New Jersey and Connecticut. 

For all the hyper-partisanship of the Reagan era, a Republican president was not a threat to democracy or America’s alliances. The 12-year GOP wave was followed by eight years of Bill Clinton in the White House. That kind of oscillation is politics in a democracy.

But the specter of a Trump restoration represents the most frightening threat to American values and the rule of law since there was glib talk about a need for a dictator at the height of the Depression. 

This is not a moment to say — as the Democrats did in the 1980s — that Mondale and Dukakis are laudable public figures, and we cannot abandon them.

The issue is not what Biden has done as president. The issue is what Biden can do in the months ahead to turn this train wreck of an election around. And, alas, I think the answer is to withdraw, because the stakes are too high for continued headless defiance of reality.

Walter Shapiro is a staff writer for The New Republic and a lecturer in political science at Yale. He is a veteran of USA Today, Time, Newsweek and The Washington Post.