WASHINGTON -- Scott Lilly was a young member of Sen. George McGovern's presidential campaign staff in the summer of 1972, and he remembers the satisfaction he felt when Mr. McGovern chose Mr. Lilly's home-state senator to be the Democratic Party's vice presidential candidate.
But a few days after the convention that nominated Mr. McGovern and his running mate, Sen. Thomas Eagleton of Missouri, Mr. Lilly said, he came to a realization. "It suddenly struck me out of the blue that they didn't know," he said, that the decision to pick Mr. Eagleton had been made without some crucial facts.
And he was right. The information he had felt obligated to share with a top campaign aide several weeks before -- that Mr. Eagleton had been hospitalized for mental health issues -- had never been passed on.
Mr. Lilly's tip "did not register," the aide, Frank Mankiewicz, said in an interview this year. "It was a very hectic time. I must have had not two things on my mind, but maybe 80."
Today, one of the legacies of Mr. McGovern's choice of Mr. Eagleton is the microscopic examination of the lives and records of potential vice presidential candidates, a ritual involving teams of lawyers and consultants and reams of medical and financial records that the candidates are obligated to produce.
Mitt Romney, the presumptive GOP nominee, has been engaged in that vetting process. And while he is renowned for his love of data, as well as his caution, every presidential candidate since Mr. McGovern has had the same goal in the vice presidential search: no surprises.
In the case of Mr. Eagleton, a number of other people besides Mr. Lilly had some inkling of his history, even if they did not have definitive proof. They included a prominent member of Mr. Eagleton's staff, many political figures and reporters in Missouri, reporters for Time magazine, and probably officials in the Nixon White House.
But Mr. McGovern, who had pledged to "avoid the messy way vice presidents had been picked in the past," chose Mr. Eagleton after considering him for less than an hour. The conversation in which Mr. McGovern offered Mr. Eagleton the slot lasted 67 seconds, and there was no mention of Mr. Eagleton's three hospitalizations for depression or the electroshock therapy during two of the stays.
Eighteen days later, Mr. Eagleton was forced to resign from the ticket in a debacle that culminated with Mr. McGovern enduring the worst defeat in presidential history.
Joel Goldstein, a St. Louis University law professor and an expert on the vice presidency, said that in 2012 "a candidate would never be asked to run without extensive prior scrutiny."
Yet in 2008, Sen. John McCain's selection of Sarah Palin, a relatively unknown Alaska governor, as his running mate reinforced the inherent dangers of a selection process that mainly involves a presidential nominee and a small group of aides.
Steve Schmidt, who was involved in Ms. Palin's selection and later publicly admitted that he regretted it, said that while McCain aides were certainly aware of the consequences of the way Mr. Eagleton was selected, there was still "a tremendous tension that exists in the vetting process between the desire for secrecy and the ability to gather the type of information that would give you a sense about how the person functions under pressure or stress."
A different time
Over the years, Mr. McGovern, who turned 90 recently, has expressed regret that Mr. Eagleton, who died in 2007, when he was 77, was not more forthcoming about his health.
"I wish, of course, that Senator Eagleton had discussed his health problem with me before I selected him," Mr. McGovern said in an interview in 2005. "I think that would happen nowadays."
But Mr. McGovern also pointed out that it was a different time, when politicians felt it was unseemly to ask delicate questions about one another.
Forty years later, in an era of continuous news delivered on Twitter and the Internet and amplified by cable television, the slow and painful unfolding of Mr. Eagleton's history and the reluctant response to it by Mr. McGovern and his aides seem unimaginable. But the story of the "18-day running mate" -- as Mr. Eagleton is called in a new history of the episode by Joshua Glasser -- remains a cautionary tale for candidates and their staffs.
An issue under wraps
As Mr. Eagleton worked his way up in Missouri politics and ultimately reached the Senate, he was careful not to disclose his medical history. From the first of his hospitalizations, news releases and euphemisms (like "undergoing tests") were used to disguise the reason for his stays.
Over the years, rumors about Mr. Eagleton's health surfaced quietly and subsided without much consequence.
"You would expect that if there was anything out there, the St. Louis Post-Dispatch would have it," Gary Hart, Mr. McGovern's campaign manager, who was later a senator and an unsuccessful candidate for president, said in an interview -- an assumption that proved to be disastrous.
Some of Mr. Eagleton's friends noted his drinking in the 1960s, according to James Giglio's biography of the senator, Call Me Tom.
"He drank quite a bit," said Mr. Lilly, who often socialized with Mr. Eagleton and who is now a senior fellow at the Center for American Progress in Washington. "Sometimes he was funny, sometimes he was frightening, sometimes he created some stirs about that. How much of what was going on was alcohol and how much bipolar? My guess is the fundamental problem was bipolar [disorder]."
A reluctant media
While a small number of journalists, politicians and health workers heard rumors or knew that Mr. Eagleton suffered from depression and had a drinking problem, no one pursued the story because of a general reluctance to investigate the personal affairs of public figures. But at least one national news organization looked into the rumors.
An editor at Time magazine heard about Mr. Eagleton's mental health issues in 1966, but the magazine did not pursue the story until 1968, when one of its reporters, Jonathan Larsen, visited Missouri to report on its Senate race. Mr. Larsen was unable to confirm the rumors about Mr. Eagleton's drinking and electroshock treatment, but he said that "we put it on record only for future reference, when and if Tom Eagleton assumes a position of higher authority."
In July, 1972, with Democrats gathered in Miami Beach for their convention and Mr. Eagleton being talked about as a possible choice for the ticket, Greg Wierzynski, then Time's Chicago bureau chief, surprised an Eagleton campaign aide by asking about the electroshock rumors. The aide later delivered a denial. So did the senator's brother, Mark, a doctor in St. Louis.
Exhausted after a long underdog campaign battling the Democratic Party establishment, Mr. McGovern and his aides spent the early days of the Democratic convention fighting off a last-minute challenge to the winner-take-all rule that had given him all the California delegates. On July 13, 1972, with the nomination finally his, Mr. McGovern turned his attention to selecting his running mate.
Until then, Mr. McGovern had focused on only one person, Sen. Edward Kennedy of Massachusetts. After Mr. Kennedy rejected the offer a final time, Mr. McGovern then tried and failed to interest two of his closest friends in the Senate, Walter Mondale of Minnesota and Gaylord Nelson of Wisconsin, in the position. His aides focused on the mayor of Boston, Kevin White, and Mr. Eagleton. They immediately realized that they had little information about either one.
Gordon Weil, Mr. McGovern's Senate executive assistant, volunteered to check out both men. Mr. Weil had only an hour or so to inquire about a rumor that a journalist had passed on to a McGovern aide concerning Mr. Eagleton's alcoholism or mental illness.
Mr. Weil's quick check turned up rumors that Mr. Eagleton drank, but not seriously, and no evidence of mental health problems. Mr. McGovern dismissed the reports on Mr. Eagleton, and he instead put more stock in his Senate colleagues' recommendations.
With a party-imposed deadline of that afternoon to pick his running mate, Mr. McGovern had to act -- and he did. He offered the nomination to a man with whom his longest meaningful conversation had lasted for 20 minutes, in the Senate steam room. "I'm flattered, and I will do whatever I can," Mr. Eagleton told Mr. McGovern in their decisive 67-second conversation, "and I hope I don't let you down."
Mr. McGovern then handed the phone to Mr. Mankiewicz, who asked Mr. Eagleton some questions but never explicitly raised the issue of his health. Mr. Eagleton, convinced that his mental health issues were behind him, later said he "took a calculated risk" in concealing his health information.
Beginning of the end
The next morning, Mr. Weil ran into Douglas Bennet, Mr. Eagleton's chief of staff, and asked him about the drinking and mental health rumors. Mr. Bennet denied the drinking problem but did describe his boss' hospitalizations and his electroshock therapy.
Mr. Weil said he "went straight upstairs after my conversation with Mr. Bennet, walked into a very crowded, noisy party and interrupted whatever discussion Gary Hart and Frank Mankiewicz were having" to tell them. They, in turn, went to Mr. McGovern, who said he assumed that the reports were the usual "kind of rumors that floated around."
While top aides and an increasing number of Democrats were urging Mr. McGovern to drop Mr. Eagleton, Mr. McGovern ordered his press secretary, Richard Dougherty, to issue a statement that he was "1,000 percent" behind Mr. Eagleton's staying on the ticket -- a phrase that would forever be associated with both men.
As the pressure mounted, Mr. McGovern vacillated, initially using others to send signals to Mr. Eagleton to carry out the pledge he had made when he said he would resign if his presence on the ticket embarrassed Mr. McGovern. On July 30, they met again, this time in Washington.
Mr. Eagleton resigned the next day, Aug. 1, after Mr. McGovern agreed that he would say the reason was not Mr. Eagleton's mental health, but the public debate over Mr. Eagleton's past mental health, which was diverting attention from important issues.
Mr. McGovern selected Sargent Shriver, a former Peace Corps director and ambassador, as his new running mate.
In his unpublished autobiography, Mr. Eagleton wrote that "electroshock was the political killer."
But, for a presidential campaign, the real killer might be something else: the unknown.