15% of Clinton supporters voted for McCain in 2008, just 6% of Sanders voters backed Trump in 2016.
[Disclosure: I caucused for Hillary Clinton in the 2008 Presidential Primary]
One of the underlying criticisms made by die-hard Clinton fans (which I once was) and many in the news media is that too many supporters of Vermont Senator Bernie Sanders voted for Donald Trump. As the argument went his group of supporters were automatically supposed to vote for the Democratic candidate and Jill Stein supporters and somehow half of right-leaning Libertarian Gary Johnson voters. Leaving out the discussion on the ridiculous Libertarian voters for Clinton argument, it begged an interesting question: Did it make a difference?
Washington Post excluded Caucus States like Iowa
A study by Brian Schaffner of the Cooperative Congressional Election Study (CCES) that was published in 2017 claimed that 12% of Bernie Sanders voters backed Donald Trump. John Sides of the Washington Post published an article about it and the media took this as evidence that it was the fault Sanders and his supporters for somehow helping Trump win. But if you look a little deeper there’s two huge flaws which the Schaffner himself explained about the study which “excludes people who said they voted but actually did not” and also “excludes people who voted in caucuses or party-run primaries, for which validated turnout data are not as readily available.”
Fourteen states held caucuses and party-run primaries which severely undercuts the whole argument that it cost Clinton the election. It excludes a lot of the caucus states (like Washington which had a caucus in 2016). Yet despite the author mentioning these two major flaws in the study, mainstream journalists ran with it as a form of confirmation bias about how Clinton lost the election to someone more unpopular than her.
So what was the actually percentage of supporters of Vermont Senator Bernie Sanders? Was there a more comprehensive study or exit poll that showed a more accurate estimate reflective of the whole country rather than half of it? How did it compare to the average crossover voters during the general election? And for comparison, what was the percentage of Hillary Clinton voters that voted for Republican John McCain in 2008?
The main issue with the Washington Post story is that it excludes supporters in caucus states who were not polled. The Rand Corporation did a much more thorough comprehensive study following the attitudes of primary voters and voting preferences from the Iowa Caucus to the Presidential Election. They polled these groups of voters six times between those periods in 2008 and again in 2016. According to the Rand Corporation study it showed 15% of Clinton voters threw their support behind McCain in 2008, while eight years later only 6% of Bernie Sanders supporters ended up voting for Donald Trump.
If you’re still not convinced then let’s take a look at the average range and compare it to a more reliable source. According to exit polls of the last four Presidential elections the average party crossover from Democratic to Republican was 9.25%. According to ABC News exit polls days before voting the total percentage of Bernie Sanders voters who ended up casting their votes for Trump was 8%, half of the number of Clinton backers who voted for Republican John McCain. That’s less than the average number of crossover voters, showing claims of delivering states to Trump as nothing more than unsubstantiated claims.
In fact if we were to assume the ABC exit poll was accurate there were more Obama-McCain primary voters than Sanders-Trump voters (9% versus 8%).
So all the assumptions that Sanders voters cost Clinton the election doesn’t hold water for this reason. The Sanders voters assumes that ALL Sanders voters were Democrats, that none of them were independents (which he won by 65% in the primaries), and that none of them were Republicans. Assuming all Sanders voters are Democrats reeks of this sense of entitlement that turns people off from politics. The fact is the winning candidate should have campaigned in Wisconsin once after the primary, if she had and reached out to left leaning people of color she would have won.