Montana Senator Jon Tester

Montana Senator Jon Tester

This year features an usually high number of competitive Senate races that could result in a candidate winning with less than a majority of the vote.

The US Senate races in Indiana, Montana, Missouri, and Maine have at least three candidates on the ballot polling at more than six percent. In these close elections the candidates in third place could end up act as a “spoiler” by drawing votes away from one of the more popular candidates, because we use an inferior voting system.

In the Indiana, Montana and Missouri senate races some recent polls have shown the Democrats with a small lead over the Republicans. Importantly, though, all three races also feature a Libertarian candidates whose current standing in the polls is greater than the margin of difference between the Republican and the Democrat.

For example the New Howey/DePauw Poll of Indiana found Democrat Joe Donnelly has a two point lead over Republican Richard Mourdock, but Libertarian Andrew Horning is currently polling at 7 percent.

This dynamic may not only potentially hurt Republicans this cycle. Angus King is the independent candidate running in the Maine Senate race but is expect to caucus with the Democrats. There is a chance that Democrat Cynthia Dill, who is currently in third place, could end up splitting enough of the the center left vote with King that it allows Republican Charlie Summers to win a plurality victory.

Indications are that most of the supporters of the Libertarian candidates would prefer a Republican-controlled Senate. Similarly, Dill’s supporter in Maine would probably prefer that King wins rather than Summers. Yet if these voters stick with their first choices and don’t switch to their second choice in the final days of the election, it could result in their least favorite candidates winning with pluralities.

If we used a sane election system, like other democracy that have run-off elections or alternative voting to deal with elections featuring more than two candidates, this won’t be an issue. Voters would be able to support their preferred candidates and still decide among the remaining candidates if their top choice was not popular enough.

Unfortunately, we are stuck with our current bad election rules. As a result a handful of third-place candidates might indirectly decide several senate race and theoretically even control of the chamber this year.

Photo by DoubleSpeak Media under Creative Commons License