The unfortunate consequence of a broken election system that discourages greater choice is that it can result in the election of individuals who don’t best represent the will of the voters. Politico is reporting that Democrats are banking on conservative third-party candidates on the ballot to help them win plurality victories.

With just six days left until Election Day, a key component of the Democratic strategy to hold the House is becoming clear: In more than a dozen close races, Democrats are encouraging and advancing little-known, conservative third-party candidates in an attempt to fracture the Republican vote enough to eke out narrow victories.

Behind-the-scenes collaboration between local Democratic officials and tea party activists in a handful of isolated races has already been reported—just last week, in suburban Pennsylvania’s open 7th District, Democratic nominee Bryan Lentz finally admitted his campaign’s role in helping a tea party candidate get on the November ballot after months of avoiding the question.

But the divide-and-conquer strategy has become more widespread—and coordinated—through television ads, robo-calls and mailers in recent weeks as races have tightened and it’s become more apparent that just a few percentage points could end up swinging the outcome in many races.

The strategy of “promoting a spoiler” has been employed by both major parties for years. Earlier this year, it came was revealed that Republicans were trying to help the Green Party get on the ballot in Texas for the same reason. And while not part of a plan, Charlie Crist’s independent candidacy is splitting the center-left vote in Florida, likely allowing Republicans an easy victory in the Senate race.

This unfortunate, but effective, strategy is going to continue as long as we use our flawed “first past the post” election system for most offices. If we followed other democracies in adopting instant runoff voting (also known as alternative voting or ranked choice voting), this type of underhanded game would disappear. Instant runoff voting allows voters to select a second and third choice their vote will go to if their first choice gets too few votes.

A system of instant runoff voting would eliminate the incentive for a major party to help put “spoiler” candidates on the ballot. Even more importantly, it would increase diversity in our elections by allowing voters to freely vote for the minor candidate that best reflects their views without the fear that they are helping to elect their least favorite candidate.