Of course history can be a guide. And it’s not just 2008.
In 2004, the Democratic Party worried John Kerry would have difficulty winning over Howard Dean’s enthusiastic supporters, many of whom had taken a vow never to vote for anyone but him. 89% of Democrats voted for him in November.
In June of 2000, nearly a third of Democrats said they would vote for George W. Bush or someone else before voting for Al Gore. 86% of Democrats voted for him in November.
Political scientists call this the “reinforcement effect,” where partisan loyalties reflect voters’ values that unite a party once an opponent in the abstract crystallizes and a general election campaign takes shape.
As the nation is more polarized than ever among partisan lines and four out of five Democrats and Democratic-leaning independents view Republicans unfavorably, there is no empirical evidence to indicate this election will be any different.
It’s understandably tempting to assume it will be due to the intensity of enthusiasm, but Clinton’s support among Democratic primary voters, including the two thirds of Sanders supporters who are already saying they will vote for her if she is the nominee, isn’t anything the party should be concerned about. Especially if Sanders throws his support behind her as he has promised to do if she wins the nomination.