In this era of hyperpartisanship, our two main political parties agree on at least one thing: independent candidates are bad (for them).

Their self-interest has led to states across the country passing laws banning candidates who lose in partisan primaries from running again in the general election, either as an independent or as a different party’s nominee.

Wisconsin has a “sore loser” law on the books, which experts say allows our two main political parties to neuter competition against their hold on power.

“The political system isn’t broken,” argues a Harvard Business School paper by Katherine Gehl and Michael Porter, using these types of laws as an example. “It’s doing what it is designed to do.”

Nearly every state in the country, except New York and Connecticut, has “sore loser” laws, according to the National Conference of State Legislatures.

The two major political parties, which are private entities, have written public laws that voters must follow to keep themselves in power, and others out, Gehl and Porter argue.

On top of weakening third parties, these restrictions also increase polarization between the two main political parties in an already extreme political climate.

Though some states explicitly bar “sore loser” candidates, many others have laws that effectively do this through specific filing deadlines and other requirements. For example, in Wisconsin, candidates are barred from running in two primaries for the same election.

Candidates who lose primary challenges in Wisconsin can still run in the general as a write-in candidate. And in 2023, Republicans in the state Legislature tried to end that practice too. The bill ultimately died the following spring. U.S. Sen. Lisa Murkowski, a moderate Republican from Alaska, followed this route to win reelection in 2010 after she was knocked out in the primary.

Wisconsin put the brunt of its restrictions on the books in the 1970s, according to the Legislative Reference Bureau, a nonpartisan agency that provides legal and research services to the state government and the public. A 1975 bipartisan law in Wisconsin merged the filing deadlines for independent and partisan candidates, and the instructions from the bill authors noted the purpose was to prevent partisan candidates from filing later as independents and running in the general election, according to Spencer Johnson with the Legislative Reference Bureau.

These laws make it more difficult for moderates to win a spot on the November ballot, said Michael Kang, a professor at the Northwestern Pritzker School of Law and an expert on elections.

“The party bases sort of filter out more moderate candidates in a lot of the instances,” Kang said. “It doesn’t have to work that way exactly, but that’s the way it works in American politics given the structure of our primary election, who votes in them, and the fact that the party bases tend to be more ideologically extreme than the median voter.”

And compared to 60 years ago, voters and especially candidates, have grown more extreme, Kang said. Part of that is due to “sore loser” laws, he said.

A casualty of increased party polarization is bipartisanship, wrote Arnold Kling in a 2021 book review. Polarization shifts the significance to the primary and away from the general election so that extreme views are rewarded and centrist views are punished.

“This makes bipartisan legislation impossible, because a representative who votes for such legislation will be branded a traitor and voted out of office in the next primary,” Kling wrote.

Without these laws, less extreme candidates could have a better chance at victory, Gehl and Porter write. Connecticut, a state with no restrictions against “sore losers,” is a case in point. In 2006, moderate Democrat Joel Lieberman lost his Senate primary but ran and won as a third-party candidate in the general election. He remained in the Senate until 2013.

Eliminating ‘sore loser’ laws faces uphill battle

Little motivation exists in state legislatures to reverse these laws because politicians aren’t usually willing to change anything that resulted in their election, Kang said.

It’s actually in the interest of state legislators in Wisconsin, all of whom are from the two main parties, to keep blocking “sore losers.”

If these laws were reversed, Kang said, a party’s base would have less power and the median voter might not have to choose between extreme candidates at the polls.

Citizens in some states, like Michigan, can bypass the state Legislature to create new laws with ballot initiatives, in which signatures are gathered to get a legally binding question on the ballot, such as, ‘Should the state ban its “sore loser” law?’ Michigan was able to break a partisan gerrymander and get more competitive political districts using this avenue.

But Wisconsin’s constitution does not allow direct democracy ballot initiatives. Lawsuits are another way citizens can undo laws the state Legislature will not, Gehl and Porter argue.