Stacey Abrams is running a less-than-subtle campaign to be Joe Biden’s vice-presidential running mate. Republicans should hope she succeeds. If selected, she would displace Sarah Palin as the least-qualified person ever to serve on a major-party ticket. Biden should understand this, because he saw firsthand how much damage Palin’s selection did to then-Sen. John McCain (R-Ariz.), the Republican presidential nominee in 2008. Preelection polls showed that 6 out of 10 Americans said Palin was not qualified for the job, and a Stanford University study found that she cost McCain more than 2 million votes.