The timing of these return nominees shows the challenges that Clinton would face. They all took place before the modern primary and caucus system. For these earlier nominees, they only needed the support of the existing political figures at the national conventions.
Since the primary and caucus system has taken hold, no politician has ever really tried to make a comeback. Mitt Romney had a high-profile flirtation last year before backing down. In years past, there was discussion about comebacks from Gerald Ford, Al Gore and John Kerry, but in each case the candidate pulled back.
It may be that being a losing candidate may have a larger negative implication for voters than for the politically connected conventioneers of old. The conventions involved significant horse-trading and a well-respected and known name would have the ability to unify the party.
Modern voters have a different standard. They are focused on winners and, as we've seen, are quick to cast away the failed candidates. In this sense, Clinton has a serious problem. She will likely be blamed for failing to triumph in easily winnable races. She was the front-runner in 2008 before being overtaken by Barack Obama. While the primary field was cleared in 2016, she was unable to put Bernie Sanders away until the last moment, sustaining significant damage to her plan for an easy race. And she was seen as the heavy favorite in November. Her campaign strategy — notably her ignoring the key Midwest states — is seen as partly to blame for the shocking defeat.
Unlike in 2016, other big name Democratic candidates are not going to decline to run in order to clear the way for Clinton. Democrats who are considering runs, like Elizabeth Warren, Cory Booker, Andrew Cuomo, are unlikely to give up their chance at the presidency. Donors, who may have withheld support from primary challengers in 2016, will not be so shy in 2020. And Barack Obama and the Democratic National Committee will no longer be giving their tacit or active support in a primary race.
One other fact to consider is that unlike Republicans, who frequently choose past candidates as their own nominee, modern Democrats shun candidates who previously ran for president. Since 1968, only Hillary Clinton and Al Gore — who had a huge advantage after serving as vice president — ran for the nomination before winning it.
Hillary Clinton's supporters may want to keep their fires burning for a rematch against Donald Trump. They could be looking at past candidates who accomplished this comeback. But recent events show that they have a significant challenge if Clinton wants to take a third run for the White House. Modern presidents don't seem to get two chances in one lifetime.
Commentary by Joshua Spivak, a senior fellow at the Hugh L. Carey Institute for Government Reform at Wagner College in New York. He blogs at The Recall Elections Blog. Follow him on Twitter @recallelections.
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