J.D. Vance, the author and venture capitalist who is seeking the Republican Senate nomination from Ohio next year, has an unusual pet issue: getting more Americans to have children.

One impetus for Vance’s advocacy on this is not always subtle. In a conversation with conservative media personality Charlie Kirk earlier this year, he explained the rationale.

“We need more American children because American families, American children are good for us,” Vance said. “They make fathers more invested — there’s all kinds of research on this. They make our economy more dynamic. They make fathers more empathetic, more invested in their communities.”

But, he noted, he is always accused of being racist for elevating new children over population increases through immigration.

“There’s just no comparison between the positive effects of children and the positive effects of an immigrant,” he said. He insisted that he loved immigrants but added that “you can’t have so many people coming to the country at a time when our own families aren’t replicating themselves” — a parallel argument to the “White replacement theory” espoused by people such as Fox News’s Tucker Carlson.

“The idea that you can just replace children with immigrants,” he added, “is — it’s a sociopathic way of looking at the future.”

At a rally over the weekend, he criticized childless liberal figures such as Sen. Cory Booker (D-N.J.) and Rep. Alexandria Ocasio-Cortez (D-N.Y.) for what he described as having no “personal and direct stake” in the future of the country.

“The Democrats are talking about giving the vote to 16-year-olds,” he said. “Let’s do this instead. Let’s give votes to all children in this country, but let’s give control over those votes to the parents of the children.”

He went on to earn some claps by saying that The Washington Post and others would disparage his idea. But, in this case, The Post will instead simply note two things. First, the idea that only people with children have any stake in the United States is bizarre and obviously indefensible, functionally similar to the idea that only landowners should be allowed to cast votes. The second is that Vance’s “let parents vote for their kids” plan probably wouldn’t actually work out the way he thinks.

Every two years, the National Opinion Research Center at the University of Chicago conducts the national General Social Survey, a broad poll of Americans on a range of social issues. Included in that survey are questions specifically about politics and children.

So, by looking at the data from 2016 and 2018 (the most recent surveys for which data are readily available), we can see that conservatives are more likely to have children than liberals — and are also more likely to have more children. About 80 percent of conservatives have children, compared to 62 percent of liberals. And 65 percent of conservatives have two or more kids, compared to about half of liberals.

But “having children” is different from what Vance is talking about, which is having kids at home. There, the divide is less stark. About 23 percent of conservatives have children under the age of 18 at home, compared to 21 percent of liberals. About 1 in 10 liberals have more than one child at home; for conservatives, the figure is 1 in 8.

The divide between how many children conservatives have and how many they have at home is in part a function of conservatives tending to be older — and therefore having more grown children. But among those under age 50, the ideological divide emerges again, with conservatives being more likely to have children than liberals. However, liberals are more likely to be under age 50 than are conservatives, with a majority of conservatives being over that age and 6 in 10 liberals being 50 or younger.

Nonetheless, parents in the United States are more likely to be conservative than liberal, both overall and of children under the age of 18. American parents of children under 6 are also more likely to be conservative than liberal.

But parents with children at home are more likely to be moderate than anything.

And that complicates Vance’s political cleverness. If we break out parentage by party, the distributions shift. Democrats and independents who lean Democratic make up 45 percent of parents in the United States; Republicans and Republican-leaning independents make up only 37 percent. Among those who have kids under 18 at home, 47 percent are Democrats or Democratic leaners and only 32 percent are Republican or Republican leaners.

The explanation is simple: Political moderates are more likely to identify as Democrats or Democratic-leaning independents than as Republicans.

This is also a key reason there are a lot more Democrats/leaners than there are Republicans/leaners. (In June, Gallup estimated that 50 percent of Americans fell into the former group and 41 percent the latter.) And it works the other way, too: Democrats are more moderate than Republicans, meaning that Vance is necessarily picking on only a part of the Democratic base.

When we apply the party divisions to our initial question, we see that there isn’t much partisan divide between Democrats and Republicans on the number of children. Even when considering Americans with two or more kids, the gap between left and right is a little smaller, and likely made up for by the larger number of Democrats and Democratic-leaning independents.

One irony here, given Vance’s complaint to Kirk that he is often accused of racism, is that liberal Democrats tend to be more densely White. Non-White Americans and immigrants tend to have higher fertility rates, leading to more children. Non-White Democrats also tend to be more moderate. So Vance, in essence, is proposing that those Democrats with kids — who are disproportionately non-White — be rewarded with more votes to cast.

Perhaps the Democrats should take him up on this proposal.