You don’t have to go to a Donald Trump rally to understand how much public abuse reporters receive, both online and in real life. Hostility toward the press is certainly more visible in the U.S. today than ever, with polls showing declining trust in newspapers, TV and radio. But a pernicious hatred toward those who bring us the news has deep roots, largely hidden in the personal archives of reporters. We need to listen to those voices and take them seriously to better understand the fault lines in American society that Trump has been exploiting.

In February 1951, one listener wrote a letter to a radio reporter, after hearing his news analysis: “Why don’t some of you boys of the Washington smear brigade get out of the Washington Press Club bar long enough—and immunize yourselves from the Washington Post editorial page long enough—to come out here to the Midwest and find out what the PEOPLE in this great populous, industrial part of the country think about things?” The comments have an eerie similarity to today’s anti-media discourse.

We must understand these echoes—and put them in the context of broader American divisions that have little to do with journalism itself—if we ever hope to build stronger public trust in what should be seen as a public good.

In a recent study, I looked at themes of antisemitism, anti-elitism and “America First” ideology in the archived mail of two radio reporters, Eric Sevareid of CBS and Elmer Davis of ABC. After digitizing about 900 letters from 1949 to 1953 from their files at the Library of Congress, I found some tropes of media hatred surprisingly unchanged over the last 70 years.

We do not have survey data on public attitudes toward the press at midcentury, yet we tend to make assumptions that trust was high. Anecdotally, the myth of a golden age of radio and television journalism, embodied by Edward R. Murrow and Walter Cronkite, persists. Perhaps a majority of Americans did have more faith in national news. That faith was not, however, universal, and the resentments highlight the worst of American white nationalism. To some Americans who were bitter about the postwar internationalist world order—defined by a permanent global U.S. military presence and participation in the United Nations and NATO—reporters represented an elite system they felt was leaving them behind. “You say we can’t go back to the old days; that we have ‘progressed’ into world leadership and all that bull. Like most of the impressionable boys … you confuse leadership with obligation to be a sucker,” a man from Mineral Wells, Tex., wrote to Sevareid. “We fear you are looking through the ‘bi-focals’ of Washington and the metropolitan area around Gotham. These two places are the most un-American spots on the globe, son.”

Such listener and reader mail provides valuable historical public opinion information missed by surveys. While letters to the editor are, and were, filtered through news organizations and over-represent civically engaged white men, fan and hate mail provide raw data from a wider audience. Further, because radio is such an intimate medium, listeners’ emotional connections to broadcasters could be intense.

And there was a lot of it. Sending physical mail may seem like a barrier to us today, but it was fairly easy in 1951, when a card simply addressed to “Eric Sevareid, Radio Commentator, Washington, D.C.,” would find its way to his desk.

I was struck by the antisemitism, often found within folders labeled “fan mail.” Neither Davis nor Sevareid was Jewish, but as members of the press—long the center of conspiracy narratives of Jewish control of elite institutions—they were targets. One of the most vicious letters Davis received came from a person who signed their name “An American,” and began, “You cunning low down Jew traitor.” That letter ended with a wish that what had happened to Jews in Germany would happen in the U.S.

Present-day antisemitism is sometimes veiled in ostensibly politer language (and sometimes not), but it is no less ubiquitous or worrying for journalists. A 2016 study by the Anti-Defamation League found 19,253 antisemitic tweets aimed at a pool of 50,000 journalists from August 2015 through July 2016. Archived mail does not lend itself to a comparable quantitative analysis, but a qualitative analysis of the discourse tells an important story of the longer history.

Not all of the negative mail was crank mail, which is not surprising. Historians including Lisa McGirr and Kim Phillips-Fein have shown that grassroots conservatism has a long history in the 20th century, rooted in specific foreign policy and economic beliefs.

Some of the letter-writers were well-informed on policy issues, for example. The mother of a son fighting in Korea was angry that Davis referred to our “European Allies.” This woman, who signed her letter “An American Mother,” wrote, “England is already speaking of playing palsy-walsy with Communist China. France, Holland, Italy as well as England have all been doing business with Soviet Russia all along.” She clearly had some basis for her opinions and her concerns should not be dismissed. She then called Davis a “big stupid fathead.”

That Trump was able to whip up so much anti-NATO sentiment makes sense, given long-standing anti-European feelings in the U.S. We know that the majority of Americans shifted from antiwar to prowar positions in the wake of the attack on Pearl Harbor. But we must remember that “America First” attitudes—rooted in a racist and anti-immigrant nationalism—were deeply felt and did not magically disappear in 1941. While NATO, founded in a 1949 treaty, was popular within Washington policy circles, most Americans resented ongoing European entanglements. In the current fight over aid to Ukraine, we see echoes of that discourse.

“Real Americans.” “A return to the doctrines of our founding fathers and the Constitution.” “Why did you ever come to this Country in the first place, and why don’t you go back there.” Listeners wrote these words to journalists in 1951. Looking beyond published records to private discourses provides a fuller portrait of the U.S. at midcentury and the resentments that linger. Handwringing about the low trust in journalism that social media and online comments make visible today is justified as long as we acknowledge it has deep roots, ones that will not disappear when Trump rallies stop.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.