Recently, the results of the American National Election Survey were released, showing troubling findings: Convictions about the perceived failures of particular racial groups were a more certain predictor of votes than income inequality or authoritarianism. Specifically, the ANES found that President Trump’s voters tended to agree more than past Republican voters with the notion that “Italians, Irish” and other immigrants “overcame prejudice and worked their way up”, and that “Blacks should do the same without any special favours”.

There are plenty of reasons to object to this way of thinking. But, foremost among them is this: Many of those immigrants presumed to have pulled themselves up by their bootstraps without “any special favours” — especially Catholic immigrants such as those from Italy and Ireland — relied upon government spending to help them get a start in the United States. For voters convinced of the myth of immigrant self-reliance, the story of these Catholic immigrants is worth considering.

In the final decades of the 19th century, the number of Catholics immigrating to the United States began increasing at a rapid rate. Catholics constituted about 13 per cent of the population in 1900; by 1998, they were about 23 per cent. The rise in the percentage of Catholics was not a smooth curve — there was a sharp jump between 1900 and 1920, a couple of decades of levelling off, and another sharp jump between 1940 and about 1970. These variations are not hard to explain: The first wave, from southern and eastern Europe, was cut off by the start of the Great War in 1914; when it began again at the end of the war, it was cut off by intentionally anti-Catholic legislation passed by Congress in 1921 and 1924. And so the large number of Catholics who had immigrated before the war assimilated as a cohort, and as a cohort contributed to the baby boom that took off after the Second World War.

In both eras of significant growth in the Catholic population, Catholics arriving in America benefited from great expansions in government intervention and government power. In the Progressive Era at the century’s beginning, both local and national government took increasing responsibility for urban infrastructure, public health and education, among other things — commitments that helped establish the stability necessary for the upward mobility of these immigrants over the subsequent generations. Good sanitation, municipal garbage collection, public schools, pure-food-and-drug laws and child labour laws all ensured that these newcomers could acquire stable footing in their new homes. In that way, large government investments helped facilitate the transition from immigrant generation to American-born and raised.

As the century wore on, this assimilating generation continued to benefit from government intervention. The New Deal and its protections for labour unions, along with the massive increase in industrial production for the Second World War, gave a boost to immigrant workers, and the building of the interstate highway system and the mortgage interest deduction made moving to the suburbs (and thus homeownership and wealth conservation) possible. Perhaps most importantly, the Serviceman’s Readjustment Act, better known as the GI Bill, helped a generation of Americans without much money to attend college. Countless American family histories follow the path from unskilled immigrant labour to college- educated professional work in two generations, and this series of programmes helps explain how.

In addition to disproportionately benefiting Catholics because such a large percentage of them were assimilating, upwardly mobile and urban, these government expansions had another feature in common — they excluded or disadvantaged African-Americans. Many New Deal programmes were not available to black people by design, not accident. Blacks were the last hired and first fired in an era of industrial expansion and often excluded, legally and illegally, from labour unions. African-Americans were also deliberately excluded from the enormous upsurge in homeownership in the postwar period, which became perhaps the single most important source of the increase in wealth for the children and grandchildren of the white Europeans who had immigrated earlier in the century.

Between the mid-1960s and the early 1980s, the federal government finally recognised the claims of African-Americans to their full rights under the Constitution as ratified and amended. The Civil Rights Act of 1964 and the Voting Rights Act of 1965 were great and historic achievements, significant steps towards righting old wrongs. But in that same period, American politics began to backtrack on the promises made to earlier generations regarding the economic stability necessary to achieving full equality. During the past 40 years, we have systematically dismantled many aspects of the social order that had enabled the rapid assimilation and ascent to wealth of the previous generation of white immigrants. With organised labour undermined, public schools systematically underfunded, homeownership further and further out of reach, and voting rights under sustained assault, many of the very gains that once helped ensure social mobility to the children and grandchildren of white European Catholic immigrants have been reversed.

Christians should care for the poor and vulnerable because doing so is at the heart of the Christian call. But somehow that call often seems to carry less weight than it should in the public arena. We often feel free to reject politics that would uplift the poorest because we don’t owe anything of what we’ve worked hard for to fellow citizens we imagine as working less hard. This is perhaps why Trump was able to win a majority of Catholic votes.

But the history of 20th-century white Catholics in America suggests that this bootstraps story is not historical. The social mobility of the Catholic immigrants of yesteryear was a result of hard work, courage and perseverance — but it was also the result of vast public investment, government subsidy and the advantage many Catholics had because they were white. At the very least, this reality of white Catholic history should call contemporary white Catholics to support levels of investment, support and trust in our fellow citizens at least as generous as those that led many of us to where we are. Rather than reinventing a mythical past about self-reliance, it’s time to pay it forward.

•Una Cadegan is an associate professor of history at the University of Dayton in Dayton, Ohio