Green Party candidate Jill Stein does not see herself as a spoiler in the 2016 presidential race. Her voters, Stein claims, would not have come to the polls had she not been in the race. But what if Stein were wrong and she didn’t bring new voters to the polls? The number of votes Stein got in Michigan and Wisconsin exceeded the gap between Clinton and Trump in those states. If you assume that Stein voters were more liberal than conservative and therefore more likely to support Clinton than Trump, Stein could have been a spoiler in those two states. Of course, winning Michigan and Wisconsin would not have given Clinton the presidency. But the question of whether third-party candidates expand the electorate has important implications in last year’s election – and in presidential elections in general. We are scholars of politics and the presidency, but you don’t need to be an expert to know that a shift or addition of just a few thousand votes in one or two key states can determine the outcome of a presidential election. In other words, a handful of voters in the right place at the right time can truly change the course of American history. And so, we decided to test the notion that third-party candidates increase turnout in presidential elections.
To start, we collected voter turnout data going back to the election of 1868. That election was the first after the Civil War and represents the earliest days of the modern two-party system.
We looked at how voter turnout interacted with the voting performance of third-party candidacies. We took into consideration the expansion of the voting franchise through the 15th Amendment, which granted universal male suffrage; the 19th Amendment, which extended the vote to women; the 26th Amendment, which lowered the voting age to 18; and the Voting Rights Act. We also compensated for historical and demographic trends.
We found that not only do third-party candidacies fail to increase turnout, they are actually associated with a statistically significant reduction in turnout. Put simply, fewer people vote in elections in which third-party candidates receive a substantial portion of the vote.
Full Article: Are third-party candidates spoilers? What voting data reveal.