The time: January 1968. The war: Vietnam. The president: Lyndon Johnson. Half a million Americans were fighting in Asian jungles, and LBJ was considering requests for hundreds of thousands more. Johnson warned against what some people were calling “cut and run.” He disdained antiwar Democrats—like his nemesis, Sen. Robert Kennedy of New York—for turning “on their leader and on their country and on their own fighting men.”

The idea of a Vietnam commission came from a surprising source: the fabled Democratic boss Richard Daley, mayor of Chicago. LBJ considered Daley a stalwart loyalist; the old Chicago bulldog was anything but anti-Establishment. But what Johnson didn’t know was that Daley was turning against the war. Too many Chicago boys—including some he knew personally—were coming back from Southeast Asia in coffins. A politician to his core, Daley knew that Vietnam could sink the whole Democratic ticket in 1968, right down to the precinct level.

Daley thought a presidential commission on the Vietnam War could find some solution that might unite the Democrats and avert a bruising election defeat. He quietly made the suggestion to Robert Kennedy, who was then considering whether to challenge LBJ for the Democratic presidential nomination of 1968. RFK was skeptical, but he agreed to raise it (through intermediaries) with President Johnson.

As the secret discussions accelerated, Kennedy implied that if Johnson approved a commission, he would not oppose LBJ’s renomination. Johnson’s large ears perked up: he was still considering a run for re-election in 1968 and, in any case, would have been willing to pay a high price to keep RFK out of the Oval Office.

But the talks broke down when Kennedy insisted that any such panel be dominated by known Vietnam “doves,” starting with Senate Majority Leader Mike Mansfield, Democrat of Montana, who had opposed the war from its start.

To Kennedy’s demand, LBJ replied, “No thanks.” RFK made his doomed campaign for president, and the rest was the sad history of four more years of war under Richard Nixon.

The stillborn Johnson commission on Vietnam has obvious parallels to the Baker-Hamilton commission on the Iraq War, released this morning. The formation of the Iraq Study Group was never President Bush’s idea. From the outset, the White House has clearly regarded its impending report less as a valuable resource than as a dangerous political firecracker whose sparks would have to be tamped down—especially when the media began treating its arrival with level of attention typically reserved for a president’s State of the Union address. History suggests that Baker-Hamilton’s ultimate contribution may be whatever outside pressure it generates on President Bush and Congress to achieve a bipartisan solution in Iraq.

The times in history when such panels have had the greatest impact have been when they provided a president with the mechanics and bipartisan blessing to do what he probably wanted to do anyway. The best two examples are both from the Reagan years. In 1981, President Reagan appointed an expert commission led by Alan Greenspan (not yet Fed chairman) to suggest how to fix that generation’s Social Security problems.

Six years later, besieged by the Iran-contra scandal, Reagan appointed a bipartisan group headed by Texas Republican Sen. John Tower to suggest how to revise White House management to exclude the future possibility of unauthorized covert operations. By promptly accepting the Tower Commission’s wise recommendations and admitting his mistakes, Reagan helped to save his presidency.

One reason the Tower findings were so briskly accepted was the expertise of the commission’s staff director, who knew how important it was for the president to take its report seriously. This was a young lawyer named Stephen Hadley, who has gone on to become President Bush’s national-security adviser. We are now about to see whether Hadley will take the same approach now that he is on the inside of the White House.

Michael Beschloss’s next book will be “Presidential Courage: Brave Leaders and How They Changed America, 1789-1989,” to be published by Simon and Schuster in May 2007.