But Ms. DeVos has often made up for what she lacks in tact through sheer force of will.

Mr. Richardville said he and Ms. DeVos disagreed over term limits, which she supported as party chairwoman and he opposed: “I said, ‘I don’t think you should be setting policy. You should be supporting those of us who do make policy.’ But she never backed down.”

While Dick and Betsy DeVos appear to practice a more tolerant form of Christianity than their parents — Ms. DeVos has spoken out against anti-gay bigotry — as recently as the early 2000s they funded some groups like Focus on the Family, a large ministry that helps set the political agenda for conservative evangelicals. They have also backed groups that promote conservative values to students and Christian education, including one with ties to the Christian Reformed Church.

Their economic views are strikingly similar to the elder Mr. DeVos’s.

According to federal disclosures, Amway, which Dick DeVos ran between 1993 and 2002, has lobbied frequently over the last 20 years to reduce or repeal the estate tax. Only the top 0.2 percent wealthiest estates paid the tax in 2015.

The company has also opposed crackdowns on tax shelters.

Ms. DeVos has been an outspoken defender of unlimited contributions known as soft money, which she described in a 1997 editorial as “hard-earned American dollars that Big Brother has yet to find a way to control.”

After Congress later passed a major campaign finance reform bill, a nonprofit that Ms. DeVos helped to create and fund masterminded the strategy that produced Citizens United, the 2010 Supreme Court decision laying the groundwork for super PACs funded by corporations, unions and individuals to raise and spend unlimited amounts in elections.

And then there are the family’s efforts to rein in the labor movement.

Through their contributions to think tanks like the Mackinac Center, as well as Mr. DeVos’s direct prodding of Republican legislators, the family played a key role in helping pass Michigan’s so-called right-to-work legislation in 2012. The legislation largely ended the requirement that workers pay fees to unions as a condition of employment.

Unions in the state bled members in 2014, the first full year the measure was in effect.

Allies say the DeVoses fight for their beliefs. “Betsy and Dick see themselves as principled conservatives,” said Frederick Hess of the American Enterprise Institute. “It kind of seems healthy and admirable to give resources to folks who are going to fight for causes you believe in.”