Steve Kornacki: What happened the last time Democrats swapped out nominees in high-profile races

Gauging the fallout from a potential Joe Biden withdrawal from the presidential race is impossible in part because nothing like it has happened before.

Biden is currently his party’s presumptive nominee. This means he secured a majority of pledged delegates during the primary campaign, assuring a first-ballot victory at the Democratic convention. It’s a designation that’s come into use over the last five decades and, in that time, every presumptive nominee from both major parties has been ratified as the actual nominee. And no presidential nominee of a major party has ever dropped out during the general election campaign.

So if Biden were now to exit and be replaced by a different candidate, there’d be no parallel example at the presidential level. But there are a few that at least come close at the statewide level, where parties have — very, very rarely — changed candidates in major competitive races long after the original selection of a nominee.

Perhaps the two most prominent cases both came in 2002, when for very different reasons, Democrats replaced their Senate nominees in two competitive races. One worked out for them and one didn’t.

An ethics cloud in New Jersey

The successful candidate switch occurred in New Jersey, where Sen. Robert Torricelli was seeking a second term. Torricelli had endured a federal investigation involving a donor, David Chang, who claimed to have showered the senator with luxury gifts and cash. In January 2002, prosecutors declined to charge Torricelli, who pronounced the matter settled, corralled party support and won re-nomination without opposition.

But federal officials also referred material to the Senate Ethics Committee, which in late July “severely admonished” Torricelli in a