Nixon said he would depart at noon the next day, Aug. 9, because it had become evident to him that he no longer had “a strong enough political base in the Congress” to finish his term. The immediate reaction to Nixon’s resignation speech was that he had once again fudged the truth. Reporters wrote that it was the Watergate scandal and the strong likelihood of his impeachment by the House and his conviction by the Senate that prompted him to quit.

Whether Nixon’s explanation made sense, the fallout that can occur when a president loses support within his own party ranks bears scrutiny. That is particularly true today, a time when opposition is steadily mounting within Republican ranks to President Bush’s plan to send more than 21,000 additional troops to Iraq.

The strained circumstances that Bush faces differ greatly from those that brought Nixon down -- although Bush’s poor standing in the polls tracks closely to Nixon’s numbers in 1974. Talk of impeaching Bush is limited to fringe Web sites -- far removed from the GOP mainstream.

But there is another critical difference as Stephen Hess, who once worked in the Nixon White House, noted.

“Richard Nixon came out of the Congress,” said Hess, who recently retired as a Brookings Institution presidential scholar to become distinguished research professor of media and public affairs at George Washington University. “The folks who came to him and told him that he had to leave were the same folks who, in a sense, he grew up with.”

“When a Mitch McConnell or a Chuck Hagel shows up in the Oval Office to tell the president he must reverse course in Iraq, Bush thumbs his nose at them -- at least up to this point,” Hess continued. “He deals with them quite differently than Nixon did with Goldwater.” (Kentucky Republican McConnell is the Senate minority leader and Nebraska Republican Hagel, a potential presidential candidate, is one of the Senate’s sharpest critics of the war.)

Sen. Barry Goldwater, Ariz., the 1964 GOP presidential nominee, was a respected conservative leader in a Senate whose Republican ranks were less conservative than now. On Aug. 6, 1974, at the regular Senate Republican Conference lunch, Goldwater fumed: “There are only so many lies you can take, and now there has been one too many. Nixon should get his ass out of the White House -- today!”

Goldwater called William Timmons, a White House aide, to set up a meeting. He told Timmons he wanted to tell the president that many GOP senators wanted him to resign.

Nixon agreed to see Goldwater on the following day. But he insisted that the top GOP congressional leaders accompany him. So Goldwater arrived with Sen. Hugh Scott, Pa., the minority leader, while Scott’s House counterpart, Rep. John Rhodes, Ariz., came separately.

“There’s not more than 15 senators for you,” Goldwater said. Nixon asked the pipe-smoking Scott for his views. “I think 12 to 15,” said Scott, who had once had defended Nixon on the basis of a doctored Watergate transcript that had been shown to him privately.

While the curtain came down quickly after that climatic showdown, portents of trouble ahead for the president were evident more than a year earlier.

In a May 1973 interview with Time magazine’s Hays Gorey, Goldwater said, “If it can be proved that he lied, resignation would have to be considered. It would be quick. Everything would be over, ended. It wouldn’t drag out like impeachment.”

But it would take a while longer before Goldwater saw the need for the president to leave. As Goldwater put it to Gorey, “Watergate is the concern of every Republican I talk to. But both conservatives and liberals in the party are ready to stand behind the president. I think he’ll continue to get support on votes in Congress, particularly on vetoes.”

Goldwater’s response illustrates an adage about political life: “If You Strike at the King, You Have to Kill Him.” That belief was around when Shakespeare wrote his plays about King Lear and Julius Caesar.

At the time, conservative sentiment favored elevating Vice President Spiro T. Agnew to the presidency if Nixon had to go. Said Goldwater, “If there is one thing the vice president can back up, it’s that he doesn’t know what the hell is going on at the White House.” In October 1973, Agnew himself would be gone, having pleaded no contest to money laundering and tax evasion charges after he resigned.

To be sure, there’s no sentiment to elevate Vice President Cheney, who knows what is going on. That said, political storms, once launched, have a way of whipping up quickly.

“It’s still too early to tell what will happen in the Congress,” Hess said. “Bush has rolled the dice. He is never going to run again. I don’t think he’s going to respond to pressure, at least for some time. And he has left himself some wiggle room.”

Andrew Glass ([email protected]) is a senior editor at The Politico.