U.S. presidential elections rarely turn on voters’ views on foreign policy. Domestic issues such as the economy and health care, are almost always seen as more important by voters.

But foreign policy can turn on the outcome of elections.

The foreign policy differences between President Donald Trump and former Vice President Joe Biden are well known. Trump offers an “America First” vision that rejects “globalism” in favor of unabashed nationalism. Biden, in contrast, favors a more internationalist approach that emphasizes cooperation with other nations and international institutions.

Yet, what is striking is not that the two candidates offer different perspectives on how America engages the world, but the fact that their respective voters increasingly share those very distinct perspectives. As a new Chicago Council survey on public attitudes on foreign policy shows, never before have Americans been so divided on these issues.

The difference between Democrats and Republicans on foreign policy can be seen across a whole host of issues, starting with their views on the coronavirus pandemic. Whereas 80% of Democrats think that the pandemic has made it more important for the United States to coordinate and collaborate with others to solve global issues, 58% of Republicans believe it is more important to be self-sufficient as a nation and not depend on others.

More generally, twice as many Democrats as Republicans (72% to 36%) believe that “problems like climate change and pandemics are so big that no country can solve them alone, and international cooperation is the only way we can make progress in solving these problems.”

Democrats accordingly favor internationalist approaches, including increasing U.S. participation in international organizations (63%), providing humanitarian aid (59%) and negotiating international agreements (55%). They also believe that international organizations such as the World Health Organization (71%), the United Nations (68%) and the World Trade Organization (53%) should be more involved in solving global problems.

By contrast, nearly half of Republicans (48%) believe the United States is “rich and powerful enough to go it alone.” Their preference is to emphasize unilateral capabilities, such as increasing the use of drone strikes (44%), imposing sanctions on other countries (43%) and placing tariffs on goods traded with other nations (43%). And when it comes to international organizations, few Republicans favor increasing their involvement in solving global problems; and a third believe organizations such as the U.N. (34%), WHO (39%) and WTO (30%) should be less involved.

The partisan differences are perhaps most starkly present on the one foreign policy issue that has penetrated the election campaign: U.S. relations with China. While views of China among all Americans has plummeted to their lowest level since diplomatic relations were established in 1978, there are still big differences on the degree to which China poses a threat and how the United States should deal with it.

Two-thirds of Republicans see China’s development as a world power as the biggest critical threat facing the United States today. Yet, while a plurality of Democrats (47%) agrees that China is a threat, they rank it just 13th on the list of 15 critical threats. And while a large majority of Republicans (64%) say the United States should actively work to limit the growth of China’s power, a similar majority of Democrats (60%) instead favor friendly cooperation and engagement with China.

This, then, may well turn out to be the most consequential foreign policy election in many decades - even if most of the voters fill in their ballots with very different concerns in mind.

Ivo Daalder is president of the Chicago Council on Global Affairs and a former U.S. ambassador to NATO.