It is hard to find anyone more passionate about the idea of steering public dollars away from traditional public schools than Betsy DeVos, Donald J. Trump’s pick as the cabinet secretary overseeing the nation’s education system.

For nearly 30 years, as a philanthropist, activist and Republican fund-raiser, she has pushed to give families taxpayer money in the form of vouchers to attend private and parochial schools, pressed to expand publicly funded but privately run charter schools, and tried to strip teacher unions of their influence.

A daughter of privilege, she also married into it; her husband, Dick, who ran unsuccessfully for governor of Michigan a decade ago, is heir to the Amway fortune. Like many education philanthropists, she argues that children’s ZIP codes should not confine them to failing schools.

But Ms. DeVos’s efforts to expand educational opportunity in her home state of Michigan and across the country have focused little on existing public schools, and almost entirely on establishing newer, more entrepreneurial models to compete with traditional schools for students and money. Her donations and advocacy go almost entirely toward groups seeking to move students and money away from what Mr. Trump calls “failing government schools.”