Did enough Bernie Sanders supporters vote for Trump to cost Clinton the election? – Washington Post
On Tuesday night, Sen. Bernie Sanders (I-Vt.) was in Detroit to host a town hall meeting with Rep. John Conyers Jr. (D-Mich.). It felt, writes The Washington Post’s Dave Weigel, like a “campaign rally.” Indeed, Sanders is still being discussed as a front-runner for the Democratic nomination in 2020.
New data is shedding light, however, on Sanders’s role in the last election — and on how many Sanders voters ended up supporting Trump. It’s a question many in the party will be asking about a candidate who may want to compete again for the Democratic nomination.
How many Sanders voters voted for Donald Trump?
Two surveys estimate that 12 percent of Sanders voters voted for Trump. A third survey suggests it was 6 percent.
First, the political scientist Brian Schaffner analyzed the Cooperative Congressional Election Study, which was conducted by YouGov and interviewed 64,600 Americans in October-November 2016. In that survey, Schaffner found that 12 percent of people who voted in the primary and reported voting for Sanders also voted in November and reported voting for Trump.
Schaffner examined only voters whose turnout in the primary and general election could be validated using voter file data. This excludes people who said they voted but actually did not — although it also excludes people who voted in caucuses or party-run primaries, for which validated turnout data are not as readily available.
Second, the same 12 percent figure emerges in the 2016 VOTER Survey, which was also conducted by YouGov and overseen by the Democracy Fund Voter Study Group (of which I am research director). In 2016, this survey interviewed 8,000 respondents in July, when they were asked their primary vote preference, and then in December, when they were asked their general election preference. This has the advantage of measuring primary preference closer to the primaries themselves and then tracking people over time. But their turnout in both elections has not been validated as of yet.
The third survey is the RAND Presidential Election Panel Survey, which interviewed the same group of about 3,000 Americans six times during the campaign. Again, this survey has the advantage of tracking voters over time, but nobody’s turnout has been validated. Among voters who reported supporting Sanders as of March 2016, 6 percent then reported voting for Trump in November.
There is no way to know whether 12 percent or 6 percent or some other estimate is The Truth, and there are enough differences among these surveys that we cannot easily pinpoint why the numbers differ. So we should take these estimates with some caution.
How does this compare to other elections?
It’s a perennial question whether supporters of losing primary candidates will vote for their party’s nominee in the general election. So let’s compare the Democratic primary with the Republican primary. In the VOTER Survey, only 3 percent of those supporting Texas Sen. Ted Cruz reported voting for Hillary Clinton, as did 10 percent of Florida Sen. Marco Rubio’s supporters and 32 percent of Ohio Gov. John Kasich’s supporters. So Sanders supporters were about as likely to vote for Trump as Rubio’s supporters were to vote for Clinton, and far less likely than Kasich supporters were to vote for Clinton.
Another useful comparison is to 2008, when the question was whether Clinton supporters would vote for Barack Obama or John McCain (R-Ariz.) Based on data from the 2008 Cooperative Campaign Analysis Project, a YouGov survey that also interviewed respondents multiple times during the campaign, 24 percent of people who supported Clinton in the primary as of March 2008 then reported voting for McCain in the general election.
An analysis of a different 2008 survey by the political scientists Michael Henderson, Sunshine Hillygus and Trevor Thompson produced a similar estimate: 25 percent. (Unsurprisingly, Clinton voters who supported McCain were more likely to have negative views of African Americans, relative to those who supported Obama.)
Thus, the 6 percent or 12 percent of Sanders supporters who may have supported Trump does not look especially large in comparison with these other examples.
Was this enough to cost Clinton support in key states?
This is a huge hypothetical, of course. Clinton’s losses in the Rust Belt, which cost her an electoral college majority, can be attributed to many factors. And a lot depends on the exact number of Sanders supporters who did not vote for her.