In the US, politicians and the news media often make a distinction between so-called “legal” and “illegal” immigrants. In new research, David Macdonald examines the effects of how the news media talks about this distinction on public attitudes towards immigrants and immigration. He finds that feelings toward “illegal” immigrants dominate opinions about general immigration policy, and are significantly linked with voters’ support for Trump, while feelings toward “legal” immigrants play little role in either feelings towards immigration policies or voting decisions.

Immigration is one of the most talked-about and important topics in contemporary American politics. As such, we have learned a good deal about the causes and consequences of public attitudes toward immigration. However, we know far less about how ordinary Americans distinguish between legal and illegal (or undocumented) immigrants, and how these attitudes may differentially shape public opinion and electoral behavior. One reason for this is that surveys rarely measure attitudes toward both groups. Fortunately, a 2019 pilot study by the American National Election Study (ANES) includes questions that ask approximately 1,500 respondents to rate, on a 0-100 feeling thermometer scale, both “illegal immigrants” and “legal immigrants.” I use this data to examine how American public opinion toward “illegal” and “legal” immigrants differ, and to test how they shape general attitudes toward immigration and refugee policy, and support for presidential candidates. I also use original content analyses of five major US newspapers to illustrate the frequency with which “illegality” is discussed regarding immigrants and immigration.

The political consequences of how the media talks about immigration

The US news media has long hyper-focused on the “illegal” aspect of immigrants and immigration. This is also not something that is unique to right-wing news outlets such as Fox News nor staunchly anti-immigrant politicians such as Donald Trump. Indeed, Figure 1 shows, using data from five major US newspapers, including four newspapers based in states that share a border with Mexico, that the terms “illegal” are mentioned far more often than the term “legal” when it comes to how immigrants and immigration are discussed. I argue that this has political consequences.

Figure 1 – Coverage of immigrants/immigration in Five US Newspapers, 2002-2023 

Note: Shows the number of articles that contain the phrases “legal immigrants”/”legal immigration” vs. the number of articles that contain the phrases “illegal immigrants”/”illegal immigration” across five US newspapers (from online archive keyword searches for each paper) from Jan 1, 2002, through Dec 31, 2023.

While the terms “illegal” and “legal” are socially constructed and determined by the peculiarities of immigration law, something that can and has changed over time, these are also real groups that the American public differentiates between, with the former being far more negatively stereotyped than the latter. Indeed, data from the 2019 ANES Pilot shows that Americans give “illegal” immigrants a rating of 43/100 compared to 72/100 for “legal” immigrants. Furthermore, “illegal” immigrant is not simply synonymous with Hispanic (the correlation between ratings of these two groups in survey data is far from perfect) nor is “legal” immigrant merely a substitute for white.

Even if such news stories are not explicitly framed in a way that portrays immigrants negatively, e.g., as not only “illegal” but also as violent criminals, drains on the social welfare state, or a threat to native citizen’s jobs, a hyper-focus on “illegality”, can still matter because, as per the psychology of priming, it can how affect how ordinary voters think about related political issues, i.e., what mental criteria they rely upon when forming their opinions.

“Immigration protest (2025-06-09)” (CC BY-NC-SA 2.0) by prescottlhm

I argue that such media coverage of immigrants and immigration, i.e., a hyper-focus on “illegality,” can affect how many Americans think about immigration policy in general. I test this using data from the 2019 ANES Pilot. The results show that feelings toward both “legal” and “illegal” immigrants separately influence general immigration policy preferences and attitudes toward refugee acceptance, both reflecting policies that are legal under federal law. However, when including measures of both attitudes in the same model, I find that feelings toward “illegal” immigrants dominate opinions toward general immigration policy, while feelings toward “legal” immigrants play little role. I attribute this in large part to how the national news media covers immigrants and immigration.

I also find that this dynamic extends to voting behavior, with feelings toward “illegal” immigrants being powerfully and significantly linked with support for Trump (vs. several then hypothetical Democratic candidates), but feelings toward “legal” immigrants being weakly and non-significantly linked with candidate evaluations. Importantly, this pattern holds up even when controlling other well-established correlates of individual-level voting behavior such as policy opinions, economic evaluations, and partisan identification.

How news coverage informs how people think about immigrants

In short, US immigration law has constructed different categories of immigrants, some “legal” and some “illegal.” I argue that the American mass public differentiates between these two socially constructed groups and, due partly to the nature of news media coverage, bringing attitudes toward the former much more strongly to bear on their general thinking about immigration and views toward political candidates.

My findings suggest that pro-immigrant politicians and interest groups would benefit from reorienting how immigration is discussed in American political discourse, and covered in the mass media. If not, it seems likely that public attitudes toward “illegal” immigrants, a socially constructed, but also an important and generally negatively stereotyped group, will likely continue to dominate the immigration debate and shape public opinion.

• This article is based on the paper, ‘The political consequences of public attitudes toward ‘Legal’ vs. ‘Illegal’ immigrants’, in Politics, Groups, and Identities. 
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• Note: This article gives the views of the author, and not the position of USAPP – American Politics and Policy, nor the London School of Economics.