When Texas lieutenant governor Dan Patrick declared earlier this year that he would remove tenure protections so that a “handful of professors” can no longer “indoctrinate students with critical race theory”, he was unwittingly repeating rhetoric from the unsuccessful side of a 100-year-old culture war. Across the United States, there at least 49 active bills that would crush the freedom to learn and teach on university campuses — 25 of the 50 states have at least one.

As a historian, I’ve studied the battles over education in the United States. Although fights for control of universities are waged on the fields of science, literature and history, they are won with different sorts of argument.

Critical race theory (CRT) emerged in the 1970s as a legal analysis of racism deeply embedded in society. Warnings against CRT are new, but the arguments mirror a 1920s-era assault on teaching evolution in US universities. Conservatives then, as now, sought to ban teaching of an accepted theory that threatened their world view.

In May 1921, the University of Wisconsin in Madison hosted an anti-evolution lecture by popular pundit William Jennings Bryan — who later became famous for arguing in the Scopes monkey trial in Tennessee, about teaching evolution to schoolchildren. University president Edward Birge, a prominent zoologist, criticized Bryan’s speech and drew national conservative fury.

Bryan demanded that Wisconsin’s instructors stop teaching evolution, and that Birge personally affirm a belief in creation as described in the biblical Book of Genesis. Otherwise, Bryan said, a sign should be posted at the entrance to campus describing its classrooms as “an arena in which a brutish doctrine tears to pieces the religious faith of young men and young women”.

Meanwhile, another campaign took aim at Howard Odum, a professor at the University of North Carolina in Chapel Hill and editor of a peer-reviewed journal, which had published two articles critical of the historical truth of Christian miracles. Conservatives called for Odum to be fired or reprimanded and for the university to support only research that affirmed Christian doctrine. In Greensboro, North Carolina, another instructor, Albert Keister, described evolutionary theory as a powerful scientific tool and accounts of six-day creation as “a form of mythology.” This fuelled calls for a state-wide law to ban teaching of evolutionary theory at public colleges and universities. Harry Chase, the president of the University of North Carolina, managed to defeat the proposed legislation.