William H. Regnery II, a reclusive heir to a Midwestern textile fortune who bankrolled some of the leading organizations and figures behind the rise of the alt-right and championed efforts to win adherents to a modernized notion of white supremacy, died on July 2 2021 at his home in Boca Grande, Fla. He was 80. A cousin, Alfred Regnery, said the cause was cancer. He began to lay the intellectual groundwork for a new movement built around strengthening what he believed was America’s founding white identity, embracing eugenics, sharp immigration restrictions and even the splintering of North America into racially pure “ethnostates.” In 2001 he founded the Charles Martel Society. The society’s main output is The Occidental Quarterly, which publishes academic-sounding essays with titles like “Reflections on Some Aspects of Jewish Self-Deception.” To give his views a more public face, in 2005 he spent $380,000 to create the National Policy Institute, a think tank designed to inject white-supremacist ideas into mainstream political conversations. But the institute languished for its first decade, even after Mr. Regnery hired the alt-right figure Richard Spencer, a charismatic former Ph.D. student, in 2011. Mr. Regnery saw Mr. Trump’s victory as his own, but he preferred to keep out of the spotlight and let Mr. Spencer speak for the institute. Mr. Regnery attended the University of Pennsylvania, where he studied political science and joined the Intercollegiate Studies Institute, a conservative student organization co-founded by Mr. Buckley. He left before graduating to work on Senator Barry Goldwater’s 1964 presidential campaign. Mr. Regnery ran unsuccessfully for Illinois secretary of state in 1994 on the Term Limits and Tax Limits Party ticket. His racism grew more explicit. He announced plans in 2004 to start a whites-only dating site. It never happened. The Intercollegiate Studies Institute, which he had joined in college, removed him from its board. William Henry Regnery II was born on Feb. 25, 1941, in the Chicago area and grew up in Hinsdale, Ill., a suburb. His father, William F. Regnery, worked for the family textile business, Joanna-Western Mills. His mother, Elisabeth (Brittain) Regnery, was a homemaker. He is survived by his wife, Judith (Page-Timson) Regnery; his brothers, Peter and Patrick; two sons from a previous marriage, William F. and David Regnery; two of his wife’s children, Robert and William T. Regnery, whom he adopted; two children with Mrs. Regnery, Jonathan Regnery and Johanna Durkin; and 12 grandchildren. Mr. Regnery was not the only member of his family active in conservative politics. His grandfather, William H. Regnery, was a founding member of the America First Committee, which sought to keep the United States out of World War II. His uncle Henry founded Regnery Publishing, which produces books by a range of conservative voices, including William F. Buckley Jr., Ann Coulter and Mr. Trump. In the years since Mr. Trump’s victory, the institute has faced mounting financial and personnel problems, especially after Mr. Spencer helped organize the “Unite the Right” rally in Charlottesville, Va., in 2017, in which a white supremacist, Alex Fields Jr., drove his car into a crowd of counterprotesters, injuring several and killing one. By 2020 the institute’s website was moribund, with no new content in months, and the Internal Revenue Service had revoked its tax-exempt status. In May a judge in Illinois ordered the institute to pay $2.4 million to Bill Burke, who was injured by Mr. Fields, but it is unclear where the money will come from.