On Friday, September 30, 2016, Republican nominee Donald Trump made his fifth campaign visit to Michigan, a battleground state where he was closing the gap with Hillary Clinton. He was scheduled to speak at five P.M. in Novi, a suburb northwest of Detroit. But instead of landing at Detroit Metropolitan Airport, his plane continued another 150 miles west to the city of Grand Rapids. The sun was peeking through the clouds over the skyline, one of the Midwest’s finest, a harmonious blend of steel-and-glass high-rises and lovingly restored old stone and red-brick buildings, when Trump’s motorcade drove through, at 12:30, and pulled up to the Gerald R. Ford Presidential Museum, named for the longtime Michigan congressman improbably catapulted into the Oval Office by the crimes of Watergate. Visitors were startled when a familiar figure—in a dark suit and unmistakable orange crown—emerged from his vehicle and placed a bouquet of roses, red and white, at the graves of Ford and his wife, Betty. Schoolchildren came racing across the lawn. A local banker called out, “Make America great again!”

By the time the motorcade reached the J. W. Marriott hotel, a cylindrical glass tower on the banks of the Grand River, the press, scrambling to catch up, had figured out what was going on. Donald Trump was in town to meet privately with donors—the cream of the city’s business class, manufacturers (Keeler Brass Company) and retailers (Cole’s Quality Foods)—gathered in the Marriott ballroom. Journalists, in the corridor outside, wondered: would the DeVoses be there?

In the solar system of elite Republican contributors, Richard DeVos Sr., who died Thursday at age 92—one of the two founders of Amway, the direct-sale colossus—occupied an exalted place, and his offspring did too. Since the 1970s, members of the DeVos family had given as much as $200 million to the G.O.P. and been tireless promoters of the modern conservative movement—its ideas, its policies, and its crusades combining free-market economics, a push for privatization of many government functions, and Christian social values. While other far-right mega-donors may have become better known over the years (the Coorses and the Kochs, Sheldon Adelson and the Mercers), Michigan’s DeVos dynasty stands apart—for the duration, range, and depth of its influence.

The last time the county voted Democratic: 1864. Against Lincoln.

Start with the think tanks, advocacy organizations, and colleges. In the Grand Rapids area alone there are three conservative academic bastions: Grand Valley State University; Calvin College, attended by several generations of DeVoses, including Rich’s daughter-in-law Betsy DeVos, 60, who is now Trump’s secretary of education; and Northwood University, her husband Dick’s alma mater. The DeVoses are also major backers of Hillsdale, the libertarian-plus-Christian liberal-arts college in southern Michigan. One celebrated alum: Betsy DeVos’s brother, Erik Prince, 49, the swashbuckling military contractor who has come to the serious attention of investigators looking into the Trump team’s alleged dealings with Russia. Other recipients of DeVos largesse: the Heritage Foundation, the Institute for Justice, and the American Enterprise Institute—the list goes on.

Top, DeVos and President Trump at the White House, April 2017. Bottom, Prince in Afghanistan, 2009. Top, by Mark Wilson/Getty Images; Bottom, by Adam Ferguson.

The DeVoses don’t limit their activism to ideas. They have been enthusiastic supporters of Republican presidential nominees—from Gerald Ford to Mitt Romney, who also has deep Michigan roots. But 2016 changed everything. Betsy, the most visible member of the clan, had been close to former Florida governor Jeb Bush; the two shared a passion for remaking public-school education. When Bush dropped out of the race, she switched over to Florida senator Marco Rubio. She also wrote checks for Carly Fiorina, Scott Walker, John Kasich, Bobby Jindal—everyone, anyone, but Donald Trump. “I’m hopeful we are going to hear something from our nominee to convince me that I should support him,” she declared at the time.

The DeVoses’ preference for “values-oriented” candidates reflect the teachings of the Christian Reformed Church. A small breakaway denomination of its Dutch forerunner, it has some 300,000 adherents in North America, many living in the same western-Michigan towns where their immigrant ancestors settled in the 1840s to pursue a faith that combines Calvinist devotion to the work ethic, prayer, a dedication to family and community—and philanthropy. The DeVoses take this seriously. Quite apart from their political donations, they have lavished millions on worthy charitable projects in and around town and far beyond. They have done all this, however, with a flamboyance unusual for Grand Rapids, stamping the family name, or Amway’s, on many of the city’s most visible surfaces.