Hillary Clinton has strongly embraced the historic nature of her bid to become the first woman president. Unlike her 2008 campaign, she has already made several gender-based appeals in the months leading up to the primaries.

Clinton even began the first Democratic presidential debate back in October by using her introductory remarks to remind Americans that with her in the White House, “finally fathers will be able to say to their daughters, ‘You, too, can grow up to be president.’”

Clinton’s message about shattering the highest and hardest glass ceiling for all of the daughters in the country should have resonated with their parents. After all, a number of social science studies show that parents of daughters are more supportive of feminist positions than parents of only sons.

This effect of having daughters on political beliefs extends, remarkably, all the way up to the U.S. Courts of Appeals.  Adam Glynn and Maya Sen have found that “conditional on the number of children a judge has, judges with daughters consistently vote in a more feminist fashion on gender issues than judges who have only sons.”

In light of those findings, we might also expect parents of daughters to be especially supportive of Hillary Clinton’s campaign to become the first female presidential nominee of the Democratic Party.

That’s exactly what these results show:

The analyses above combine the five biweekly YouGov/Economist surveys conducted since Joe Biden announced he would not run for president. Taken together, these data reveal a large effect of child’s sex on support for Hillary Clinton.

The first columns of the display, in fact, shows that parents of daughters are 14 percentage points more likely to support Hillary Clinton in the primaries than parents of only sons.  The error bars in the figure suggest that the effect of having a daughter on support for Clinton is somewhere between 8 and 20 percentage points.

The remaining columns also indicate that this “daughter effect” on Clinton support is consistent for all kinds of parents.  Mothers and fathers alike, regardless of how many children they have, are more likely to support Hillary Clinton in the primaries if they have a daughter.  Additional analyses also uncovered a statistically significant effect of daughters on support for Clinton among white, African American, and Hispanic parents.

It remains to be seen, though, whether this large and consistent impact of parenting daughters will extend into support for Hillary Clinton’s probable general election campaign. Clinton’s gender could be less of a factor in such a partisan election, where Americans who explicitly want to vote for (or against) a female candidate may have to cross party lines.

Regardless of what eventually happens down the road in November, the results strongly suggest that Clinton’s gender is currently a major factor in voters’ decisions to support her bid to become the first female nominee of the Democratic Party.

Michael Tesler is assistant professor of political science at UC Irvine, co-author of Obama’s Race, and author of the forthcoming Post-Racial or Most-Racial? Race and Politics in the Obama Era.