The Republican Party leans much farther right than most traditional conservative parties in Western Europe and Canada, according to an analysis of their election manifestos. It is more extreme than Britain’s Independence Party and France’s National Rally (formerly the National Front), which some consider far-right populist parties. The Democratic Party, in contrast, is positioned closer to mainstream liberal parties.

Note: Circles sized by the percentage of the vote won by the party in the latest election in this data. Only parties that won more than 1 percent of the vote and are still in existence are shown. We analyzed parties in a selection of Western European countries, Canada and the United States.

These findings are based on data from the Manifesto Project, which reviews and categorizes each line in party manifestos, the documents that lay out a group’s goals and policy ideas. We used the topics that the platforms emphasize, like market regulation and multiculturalism, to put them on a common scale.

The resulting scores capture how the groups represent themselves, not necessarily their actual policies. They are one way to answer a difficult question: If we could put every political party on the same continuum from left to right, where would the American parties fall?

According to its 2016 manifesto, the Republican Party lies far from the Conservative Party in Britain and the Christian Democratic Union in Germany — mainstream right-leaning parties — and closer to far-right parties like Alternative for Germany, whose platform contains plainly xenophobic, anti-Muslim statements.

The Republican platform does not include the same bigoted policies, and its score is pushed to the right because of its emphasis on traditional morality and a “national way of life.” Still, the party shares a “nativist, working-class populism” with the European far right, said Thomas Greven, a political scientist at the Free University of Berlin who has studied right-wing populism. These parties position themselves as defenders of the “traditional” people from globalization and immigration, he said.

The Republican Party vs. Other Right-Wing Parties Changed name to distance from links to racism. Wants ban on wearing burqas in public. Committed to “Western Christian culture.” Has roots in white nationalism. 4 2 8 6 5 7 1 9 3 Republican Party Proposed Muslim-only prisons. Ties with a far-right extremist group. Campaigned against climate action. Does not accept a “multiethnic society.” Wants to shut down mosques. 1. U.K. Independence Party (Britain), 2. National Rally (France), 3. Freedom Party (Austria), 4. Sweden Democrats (Sweden), 5. Finns Party (Finland), 6. Alternative for Germany (Germany), 7. Danish People’s Party (Denmark), 8. Swiss People’s Party (Switzerland), 9. Party for Freedom (Netherlands) Has roots in white nationalism. Committed to “Western Christian culture.” Changed name to distance from links to racism. Wants ban on wearing burqas in public. 4 2 8 6 5 7 1 9 3 Republican Party Proposed Muslim-only prisons. Campaigned against climate action. Wants to shut down mosques. Ties with a far-right extremist group. Does not accept a “multiethnic society.” 1. U.K. Independence Party (Britain), 2. National Rally (France), 3. Freedom Party (Austria), 4. Sweden Democrats (Sweden), 5. Finns Party (Finland), 6. Alternative for Germany (Germany), 7. Danish People’s Party (Denmark), 8. Swiss People’s Party (Switzerland), 9. Party for Freedom (Netherlands) Has roots in white nationalism. Committed to “Western Christian culture.” Changed name to distance from links to racism. Wants ban on wearing burqas in public. 3 2 7 4 5 6 1 8 Republican Party Proposed Muslim-only prisons. Does not accept a “multiethnic society.” Campaigned against climate action. Wants to shut down mosques. 1. U.K. Independence Party (Britain), 2. National Rally (France), 3. Sweden Democrats (Sweden), 4. Finns Party (Finland), 5. Alternative for Germany (Germany), 6. Danish People’s Party (Denmark), 7. Swiss People’s Party (Switzerland), 8. Party for Freedom (Netherlands)

The difference is that in Europe, far-right populist parties are often an alternative to the mainstream. In the United States, the Republican Party is the mainstream.

“That’s the tragedy of the American two-party system,” Mr. Greven said. In a multiparty government, white working-class populists might have been shunted into a smaller faction, and the Republicans might have continued as a “big tent” conservative party. Instead, the Republican Party has allowed its more extreme elements to dominate. “Nowhere in Europe do you have that phenomenon,” he said.

The situation predates the current administration, Mr. Greven said. While we could analyze Republican manifestos only through the 2016 election, since then, President Trump has openly expressed approval for politicians like Marine Le Pen, the far-right leader of France’s National Rally, who was recently ordered to stand trial for posting pictures on Twitter of killings by the Islamic State.

The Democrats fall closer to mainstream left and center-left parties in other countries, like the Social Democratic Party in Germany and Britain’s Labour Party, according to their manifestos’ scores.

And the United States’ political center of gravity is to the right of other countries’, partly because of the lack of a serious left-wing party. Between 2000 and 2012, the Democratic manifestos were to the right of the median party platform. The party has moved left but is still much closer to the center than the Republicans.

Republican Party Democratic Party 2016 2016 Labour (Britain) Conservatives (Britain) 2012 2012 In 2012 and 2016, the Democratic manifesto moved left, placing greater emphasis on labor groups, equality and market regulation. In 2008, the Democratic and Republican manifestos emphasized many of the same topics, including international cooperation and the need for a strong, stable government. 2008 2008 2004 2004 Median party 2000 2000 Democratic Party Republican Party 2016 In 2012 and 2016, the Democratic manifesto moved left, placing greater emphasis on labor groups, equality and market regulation. 2012 In 2008, the Democratic and Republican manifestos emphasized many of the same topics, including international cooperation and the need for a strong, stable government. 2008 2004 Labour (Britain) Conservatives (Britain) Median party 2000 Democratic Party Republican Party 2016 2016 Conservatives (Britain) Labour (Britain) 2012 2012 In 2012 and 2016, the Democratic manifesto moved left, placing greater emphasis on labor groups, equality and market regulation. In 2008, the Democratic and Republican manifestos emphasized many of the same topics, including international cooperation and the need for a strong, stable government. 2008 2008 2004 2004 Median party 2000 2000

To calculate these scores, we used a statistical technique called correspondence analysis, analyzing how frequently the party platforms mention each topic coded by the Manifesto Project. Each mention of a particular category pushes the party’s score to the left or the right.

To see how it works, here’s part of the Republican platform, which lauds free enterprise and traditional morality:

An Excerpt from the 2016 Republican Party Platform Pushes score left Pushes score right

Left and right roughly map onto today’s notions of progressive and conservative, though newer issues like climate change don’t always fit neatly into those buckets, and the meaning of left and right can shift from country to country. In our study, the categories that contributed most to the left-right scores were both economic, like Marxist analysis, and social, like references to a “national way of life.”

Categories that push a manifesto’s score farthest … … to the right Traditional morality Multiculturalism (–) Welfare state limitation Education limitation National way of life Free enterprise Internationalism (–) Labor groups (–) European community (–) Military … to the left Peace Keynesian demand management Constitutionalism (–) Traditional morality (–) Controlled economy Nationalization Anti-imperialism National way of life (–) Military (–) Marxist analysis (–) corresponds to a negative reference Categories that push a manifesto’s score farthest … … to the right Traditional morality Multiculturalism (–) Welfare state limitation Education limitation National way of life Free enterprise Internationalism (–) Labor groups (–) European community (–) Military … to the left Peace Keynesian demand management Constitutionalism (–) Traditional morality (–) Controlled economy Nationalization Anti-imperialism National way of life (–) Military (–) Marxist analysis (–) corresponds to a negative reference

The Republican Party’s position among the European far right is especially striking because of the United States’ two-party system, which leaves less room for fringe groups. As a result, parties are “forced to deal in platitudes, usually in competing for the center,” said Richard Bensel, a professor of political science at Cornell.

But, he added, there’s “something very strange happening in recent American politics”: Theory says that two-party systems generate “moderate, unprincipled parties,” but the Republicans and Democrats have grown more distinct.

“Democracy doesn’t work with that kind of polarization,” he said.