At the end of an ugly second presidential debate, when asked to each say something they respect about the other candidate, Hillary Clinton praised Donald Trump’s children. “His children are incredibly able and devoted, and I think that says a lot about Donald,” the Democratic nominee said. “I don’t agree with nearly anything else he says or does, but I do respect that.”

Trump’s children have been widely viewed as his greatest source of pride and biggest campaign asset. The lack of controversy surrounding Trump’s “nontraditional” family, which includes five children from three marriages, is noteworthy — especially considering how the changing structure of American families is often viewed by Republicans as shameful, not something to be proud of.

But the fact that Trump’s family is praised rather than derided is a privilege reserved almost exclusively for wealthy white men. Imagine the public response if either President Obama or Hillary Clinton had children from three different partners. That would have likely barred them entirely from high-level politics. As Trump and others like him make plain, concerns over family structure are just another way to make judgments based on class, race and gender.

Clinton and Trump actually just complimented each other (The Washington Post)

Such judgments are often supported by supposedly “objective” social science research on family structure that perpetuates bias already present in society at large. In recent years, family researchers and demographers have become increasingly concerned with an emerging trend they termed “multi-partner fertility.” It’s a fancy way to talk about individuals who have children with more than one partner. When the term first emerged about a decade ago, it was largely descriptive, a way of noting that, for a growing number of families, marriage and childbearing are increasingly decoupled. More than half of all births to millennials (those under 35) now occur outside of marriage, and 28 percent of women in the United States with two or more children have children by different men. Trump seems like the poster child for multi-partner fertility.

As studying “multi-partner fertility” became more popular, researchers began to focus not simply on its prevalence, but on its implications. Low-income women of color who have children with more than one man often became the focus of these studies. Because wealthy white men and women who have children with more than one partner are not the focus of the research on multi-partner fertility, they are largely exempted from conclusions about its dire consequences, such as increased substance abuse, poor educational outcomes and behavioral issues.

When you contrast the research on multi-partner fertility with research on “blended families”  — formerly referred to as step-families — the biases become even more apparent. This shift in language has helped reduce stigma. Even the right-wing conservative behemoth Focus on the Family, not exactly fans of any kind family other than a nuclear one, has a Blended Families page on its website, where the organization concedes that “with the right resources and the help from God, family, and friends, your step-family can find encouragement and hope.”

What’s the difference between being part of a “blended family” and having multiple “baby daddies”? You know the answer. When something becomes a trend among the middle- and upper-classes, it’s legitimized. And when it’s highly correlated with poverty or race, it’s pathologized.

The words we use matter. Apart from being insulting to millions of families who take as much pride in their children as Donald Trump takes in his, the lack of transparency in research on multi-partner families leads to misguided policy discussions. Researchers are very good at spotting trends — such as nonmarital birthrates or the increase in children born to multiple partners.

But often, the questions they ask about those trends are the wrong ones. Researchers often mistake correlation with causation, treating the relationship between family structure and the variety of negative outcomes as though they are simply the result of individuals making bad choices. Rather than asking how economic inequality, or racial inequality in the criminal justice system, lead to negative outcomes, they look at the circumstances under which people have kids. Researchers worry that families with multiple-partner fertility are more likely to be “poor, uneducated and minority,” even as they acknowledge that these families actually start off with significant disadvantages. Many researchers rely on data that make largely artificial distinctions between marriage and unmarried, or two-parent and single-parent families. They argue that two married parents are better than one without asking about the quality of the relationship between the two married parents (maybe it’s toxic or abusive?), or the quality of the single-parenting.

As a result, such studies often suggest the wrong solutions. It was this type of type of research, for example, that inspired George W. Bush’s administration to sink tens of millions of dollars into programs promoting marriage a decade ago. In addition to being paternalistic, the programs did not alleviate poverty or increase marriage rates.

Rather than asking questions that place the so-called problem of a trend like multi-partner families in the lap of the individual — usually women — doing her best to raise her family, we should ask why anyone should be expected or required to marry. Or why having children with multiple partners is viewed as acceptable for some people, and irresponsible for others. Better yet: Let’s focus more attention on the types of support that would help economically struggling families thrive.

When it comes to intimate relationships, marrying or not, and having children or not, people will make the decisions that make the most sense to them. Right now, only wealthy white men like Donald Trump have the luxury of making those choices without being policed for them. That should offend us all more than it does.