Why is it so challenging for a third political party to gain traction?

During the 2016 presidential election, the most common question I was asked concerned whether or not a third party could gain a foothold nationally. Indeed, polls at the height of the general election campaign indicated Gary Johnson, the Libertarian Party’s candidate for president, had nearly double-digit support. Certainly, the surprising success of Vermont Senator Bernie Sanders’ primary campaign for the Democratic nomination had many of his supporters begging him to mount a third-party challenge, rather than endorse Hillary Clinton.

On occasion, third-party candidates and independents win elections at the local and sometimes state levels. Peter Schwartzman is a Green Party alderman in Galesburg, for example; Jesse Ventura won the governorship of Minnesota in 1998 as a member of the Reform Party. In addition to Sanders, Senator Angus King of Maine identifies as an independent—though both caucus with the Democrats for organizational purposes. Yet these sporadic successes have never translated into sustained national success.

It’s not as if there isn’t an expressed desire. The Pew Research Center routinely asks survey respondents whether they consider themselves Democrats, Republicans or independents. From January to August 2016, more than 8,000 individuals responded, and 34 percent identified as independents. The question then to be asked: Why does the United States have a two-party system?

Historical Circumstance
There are a number of reasons why the U.S. has only two political parties capable of winning on a large scale. First, we can thank historical circumstance. At its founding, the leaders of government, while sharing a great deal in common, split on a number of issues. The Federalists, led by Alexander Hamilton, advocated for a stronger centralized national government that promoted economic development through a national banking system. Conversely, the Democratic-Republicans, led by future presidents Thomas Jefferson and James Madison, wanted more power for the states and individuals. Therefore, from the very beginning of this country, we have only had two political parties.

The Stability of Two
Secondly, two political parties provide a great deal of stability. Because we established only two political factions at the founding, it has been difficult for a third party to gain traction. Historically, when third parties have gained traction, they have “taken” votes from one of the two dominant parties—meaning two parties split a base of voters previously “owned” by one party.

For instance, the People’s Party, also known as the Populist Party, briefly played a major role in American politics. From 1892 to 1896, the party won more than eight percent of the national presidential vote, five states in the Electoral College and 10 percent of the vote in the House of Representatives. But its support base overlapped that of the Democratic Party, meaning voters split their support across two different parties rather than concentrating their support in one party. While the Democrats won the White House in 1892 with Grover Cleveland, they did so without the People’s Party’s endorsement. That victory came by virtue of only a plurality of the vote, and Cleveland’s voters were concentrated in the South, meaning he lacked national appeal.

As a result, the Republican Party gained control of the House of Representatives in 1894 and held that control until 1910. After their losses in the 1894 election, the Populists faced a difficult decision: put forward their own candidate in 1896, or fracture support across Democrats and Populists—and possibly hand the presidency to the Republicans. They chose to cross-nominate the Democratic nominee, William Jennings Bryan, while choosing to nominate their own preferred candidate for vice president. This visible fracture within the shared support of the Democrats and the Populists allowed the Republicans to win the presidency with William McKinley.

This historical anecdote illustrates the challenges third parties face: nominate their own candidates and likely lose and have the candidate ideologically closest to them lose, or face co-option by one of the two major parties. And even if the third party does survive (as the Republican Party did in 1860), it only supplants one of the existing major parties (in this case, the Whigs), leaving us with a two-party system, just one consisting of a different set of two parties.

Duverger’s Law
For various reasons, electoral laws disincentivize voters from casting ballots for third parties. In Congress and in most state legislatures, representatives are elected in single-member districts: voters elect one person to represent a single district. Most jurisdictions in the United States employ plurality voting rules, also known as “first-past-the-post” voting. Under plurality rules, a candidate need only win more votes than any other candidate—not a majority of the vote—to win the election. Thus, Candidate A can win with, say, 42 percent of the vote, while Candidates B and C split the remaining vote at, say, 38 percent and 20 percent respectively. While Candidate A received more votes than either Candidate B or Candidate C, more people voted for someone other than Candidate A. Nevertheless, Candidate A wins the election.

In political science, there is something known as Duverger’s Law: single-member districts plus plurality voting usually result in a two-party system. Why? Voters cast ballots strategically in this context. If they vote for a third-party/independent candidate, they feel they’re “wasting” their vote because only one person can win the election—and that person is likely to be the Democrat or Republican. Rather than “throwing away” their vote, the second-favorite candidate is chosen instead.

If we had multi-member districts, the same voters could vote for that third-party/independent candidate, and that candidate might still be elected, even if he or she didn’t receive the most votes—because more than one candidate gets elected. If we employed majority voting, there would potentially be a run-off between the top two candidates, allowing voters a “second chance” to cast a ballot.

Ballot Access Laws
Across the country, ballot access laws make it challenging for third-party candidates to actually get on ballots. The Illinois Libertarian Party won a victory last February when a federal judge ruled unconstitutional a state law mandating that third parties that want to run candidates in any state-level race must run a full slate of candidates in every state-level race. (The State of Illinois is currently challenging this ruling.)

Ballot access laws gained a further spotlight in the 2016 election for Illinois’ 13th Congressional District. According to Illinois law, independent candidates must gather signatures of “not less than five percent nor more than eight percent... of the total number of persons who voted at the next preceding regular General Election within the congressional district.” In that district, Democratic and Republican candidates needed to secure about 740 valid signatures to appear on the ballot. David Gill, running as an independent, needed to secure 10,754 signatures. After a protracted legal battle in which he failed to gain enough valid signatures, Gill dropped out of the race.

Human Psychology
Finally, human psychology interferes with the viability of third parties in the United States. The modern Democratic Party dates to around 1830 and is the world’s oldest active political party. The Republican Party dates back to the mid-1850s. Many individuals have grown up and been socialized to identify with one party or the other.

Furthermore, even independents usually aren’t all that independent. Research shows the vast majority of self-identified independents actually vote reliably for one political party. That means “independents” are often just as partisan as those who openly identify as Democrats or Republicans!

Rules of the Game
America has an entrenched two-party system, and because that entrenchment is multifactorial, it is difficult to budge. For a third party to achieve national prominence for an extended period of time, electoral rules and ballot access laws would need to change across the majority of the country. In addition, Americans themselves would need to undergo a radical alteration in their political identities.

While it’s certainly possible for a third party to emerge, it’s not probable. But if a third party is your dream, focusing your efforts on changing the election laws at the state level is likely the most productive place to begin. The current system is simply not designed to allow third parties to win nationally—and even if they did, we would still have a two-party system, with a different set of two parties. To actually have more than two viable parties, the rules of the game need to change.

And for those of you who believe third parties alter electoral outcomes, there’s not a great deal of evidence to back up those claims. In 1992, for instance, incumbent President George H.W. Bush lost to the Democratic challenger, Bill Clinton. Many Bush supporters claimed their candidate would have won had Ross Perot, an independent, not been on the ballot. The same line of reasoning returned in 2000 when Vice President Al Gore lost the Electoral College to Texas Governor George W. Bush: had Ralph Nader not been on the ballot, Gore might have won both the popular vote and the Electoral College.

Now that former Secretary of State Hillary Clinton has lost in the Electoral College to businessman Donald Trump, some Clinton supporters argue she would have won not only the popular vote, but also the Electoral College, if the Libertarian Party’s Gary Johnson or the Green Party’s Jill Stein had not been options. However, this argument makes two major assumptions: that those who voted for third-party candidates would have turned out to vote in the first place, and that if they had, they would have all cast their ballots for the candidate who lost. But even if they did show up, there’s no reason to assume that, say, Johnson voters—who should fit with Democratic stances half the time and Republican stances half the time—would automatically vote for Clinton. Indeed, it’s likely they would have split relatively evenly across both candidates, just as it appears Perot voters did in 1992. iBi

Megan Remmel is an assistant professor in the Political Science Department at Bradley University