So it's the week before the Republican National Convention and we don't know who the vice presidential running mate is going to be. Then the nominee schedules a Saturday midday event and walks onstage with a younger man from Indiana who is known for his ardent conservatism.

Sound familiar?

The year is 1988, the city is New Orleans, and the freshly announced GOP ticket is George H.W. Bush for president and Dan Quayle for vice president.

Surprised? Well, plenty of people were stunned at the time, too. Quayle was a senator but barely over 40, younger still in appearance and demeanor. He had been on some lists of prospects, but not near the top. His selection left many in the party and the media agog.

Donald Trump may have had something like that high-drama reveal in mind for the Hilton Ballroom on Friday. That was the moment he planned to bring out Gov. Mike Pence, who, like Quayle, is a former Indiana congressman who had made it to statewide office.

But sometimes things go awry. First, Trump's choice of Pence began to leak on Thursday and got widely reported. Very widely reported. Trump tried to reel it back in by telling a Fox News host he had not made his "final final decision." There have been reports that Trump was still having serious doubts about Pence on Thursday night, looking for a way out.

But in the moment, neither the candidate nor anyone else on his team was willing to shoot down the Pence story directly. So on it flew, hour after hour on cable TV, landing on front pages all over the country. And it persisted as news even in the midst of tragedy.

Just as the Pence drama was unfolding, an attacker with no apparent ties to any known terrorist group drove a truck into a huge crowd watching Bastille Day fireworks in Nice, France. More than 80 people were killed, more than 200 injured. Trump saw the horror on TV and impulsively tweeted a postponement of his planned announcement.

On Friday, however, the magnitude of the dilemma became apparent. Pence had to withdraw officially as the Republican candidate for governor by noon, as Indiana state law forbids running for two offices at once. So Trump, again via Twitter, announced Pence as his pick at 11 a.m. The original Hilton event was put forward to Saturday, when the two men will greet the world for the first as a ticket.

If that reminds some folks of the Bush-Quayle rollout in 1988, it may also conjure up memories of those two candidates holding their first news conference together several days later. It was then that Quayle looked unready for the national limelight, giving rise to controversies about his military history and intellectual capacity that dogged him throughout the campaign and beyond (even though he and Bush won that November).

Of course, Quayle's difficulties pale in comparison with those of some other surprise nominees for vice president. In recent history the unluckiest was surely Sarah Palin, who was governor of Alaska but largely unknown before John McCain tapped her as his No. 2 in 2008. McCain was trailing in the polls and his team thought they needed to shake things up. They introduced her on the Friday before the GOP convention, where Palin delivered an electrifying acceptance speech. But after that, her performance was uneven at best and may have hurt McCain more than it helped him.

The same might be said of Jack Kemp, the high-energy football star and congressman whom Bob Dole turned to for help in 1996. Kemp added a kick to the GOP San Diego convention but the initial thrill was gone well before Election Day.

Still, the granddaddy of all vice presidential blowups has to be the Tom Eagleton fiasco in 1972. George McGovern was the longest of long shots winning the Democratic nomination that year, uncertain of victory until the voting at the convention itself. So when he turned to the running mate issue, time was absurdly short.

McGovern chose a colleague in the Senate, a fellow Midwesterner just as liberal as he was. They held up their hands together on the convention's last night in Miami, but within days it was reported that Eagleton's bouts with depression had been treated with electroshock therapy. Soon McGovern's pledge to stand by his man "a thousand percent" succumbed to pressure. Eagleton left the ticket; McGovern struggled even to find a replacement. In November, the Democrats lost 49 states.

The 49-state winners that year were the incumbent Republicans Richard Nixon and Spiro Agnew, twice elected but star-crossed in their own way. Nixon had passed over a number of distinguished Republicans in 1968 when he first chose Agnew, holding a meeting at the convention with a small circle of aides before announcing the name.

As governor of Maryland, Agnew had not been especially distinguished, and he brought little to the party beyond a talent for the "attack dog" role often assigned to vice presidents. He did not hurt Nixon in either 1968 or 1972 but he contributed to the scandal-plagued legacy of the administration when he was indicted for corruption in 1973.

The commonality in these cautionary tales is the speed with which the final selections were made, leaving little time for thorough vetting and testing. In some cases, choices were made in haste because a window of opportunity was closing — perhaps with the convention actually underway. But just as often, candidates and their retinues rushed because they feared their decision would leak to the media before they could announce it.

There has not been a perfect record of success for vice presidents chosen with greater deliberation, of course. Bill Clinton's choice of Al Gore in 1992 probably helped him; Gore's choice of Joe Lieberman in 2000 was probably a wash. John Kerry chose his primary rival, John Edwards, as his running mate in 2004, and again it probably made little difference either way. Both tickets lost close elections, but neither Lieberman nor Edwards was really at fault. Mitt Romney in 2012 filled out his GOP ticket with Paul Ryan, who emerged with his political trajectory intact when Romney fell short.

Perhaps no one has had a more thorough approach than George W. Bush, whose selection team was headed by Dick Cheney. Bush was impressed, and chose Cheney. Whole books have been written about what happened next, and the relationship of the two men will be debated forever.

But even if a well-chosen vice president does not give a ticket the boost it ultimately needs, it may be enough for the running mate to run a good race and do no harm.

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