President Obama asked the country for tolerance towards Muslims during his televised speech to the country on Sunday. As the president put it,

We cannot turn against one another by letting this fight be defined as a war between America and Islam. That, too, is what groups like ISIL want. ISIL does not speak for Islam. They are thugs and killers, part of a cult of death, and they account for a tiny fraction of more than a billion Muslims around the world — including millions of patriotic Muslim Americans who reject their hateful ideology.

But Obama’s message was unlikely to resonate with those that it needed to reach. Political science research shows that Americans who dislike Muslims also have an especially unfavorable opinion of Obama. The most anti-Muslim, in fact, dislike Obama considerably more than any other high-profile politician.

Similarly, Donald Trump’s call for “a total and complete shutdown of Muslims entering the United States” on Monday may have had special resonance with Trump supporters. After all, even in 2011, Trump’s strongest supporters were people who thought Obama was a Muslim.  More generally, the majority of Republicans evaluate Muslims unfavorably, with Republicans and Republican-leaning independents rating Muslims substantially lower than any other religion.

Even more relevant are these new results from a November 19-23 YouGov/Economist survey. This poll shows that Trump’s supporters are particularly suspicious of Muslims.

Two questions in that survey asked about the threat of Islam to the United States: (1) How serious of a threat do Muslims pose to the United States? and (2) What share of Muslims worldwide do you think support ISIS?

The graph below shows the relationship between answers to these questions and Trump support:

Republicans who think Muslims pose an immediate threat to the United States are more than 30 percentage points more supportive of Trump than Republicans who think Muslims are not a threat to the country.

Likewise, GOP primary voters who said that most Muslims support ISIS are 35 points more likely to support Trump than Republicans who think “very few” adherents of Islam support the terrorist organization.

Trump’s strong support among Americans who have an unfavorable opinion of Muslims is not surprising. Research by Karem Ozan Kalkan, Geoffrey Layman, and Eric Uslaner shows that Americans’ attitudes towards Muslims are closely related to feelings about minority groups like undocumented immigrants and welfare recipients “that many citizens view as not conforming to conventional cultural norms and traditional values.”

Donald Trump has made several statements hostile to such cultural outgroups. The upshot is that attitudes about immigrants and Muslims are strongly correlated with support for Trump.

For this reason, Trump’s call to end Islamic immigration is unlikely to offend his strongest supporters.  Indeed, over half of Trump primary supporters already thought Muslims posed an immediate threat to the United States and that a majority of Muslims worldwide support the Islamic State — and this was even before the San Bernardino terrorist attack.

Michael Tesler is Assistant Professor of Political Science at UC Irvine, co-author of Obama’s Race, and author of the forthcoming, Post-Racial or Most-Racial? Race and Politics in the Obama Era.