New research has found that despite shifting political and societal trends over the last eight years, Republicans continue to be more likely to be married than Democrats.

In a report published by the Institute for Family Studies (IFS) last week, researchers Brad Wilcox, Wendy Wang, and Sam Herrin found that despite a “series of realignments reconfiguring the relationship between partisanship and key axes of identity in American life today … Republicans continue to be markedly more likely than Democrats to be married — and this is true for several subgroups in the population.”

While an overall decline in marriage has been occurring for some time in the U.S., the authors observe that a sizable “leftward lurch” of the Democratic Party over the last decade has likely contributed to Democrats abandoning the institution at a much higher rate than Republicans. The latest data shows that 65% of Republicans ages 25-64 are married, while only 50% of Democrats are married in the same age range.

As the authors point out, this lurch includes the fact that “most progressives today do not think that ‘children are better off if they have two married parents,’ even though the science points clearly in the other direction.” Other factors include the Left’s recent embrace of polyamory, which has likely contributed to a drop in support for fidelity. “Democratic support for the classic fidelity norm — that having sex with someone besides your spouse is ‘always wrong’ — has fallen about 30 percentage points, especially among college-educated Democrats,” the authors note. They further point out that “only 46% of college-educated Democrats agree that sex with someone other than one’s spouse is ‘always wrong’ — compared to more than 80% of Republicans who embrace” the principle.

The IFS report further highlights that “Republicans continue to enjoy significantly happier marriages and somewhat more stable families with children than Democrats.” An IFS analysis of 25 to 64 year-olds found that 65% of Republicans say they have “very happy” marriages, while only 54% of Democrats say the same.

Wilcox argues that this is likely due to the fact that conservatives tend to embrace “values like the importance of marriage, sexual fidelity in marriage, the idea that men and women are inherently different, and the value of religion.”

The authors conclude by lamenting that “declining Democratic (and progressive) support for the institution of marriage, and the values and virtues that sustain it, are likely to deepen the falling fortunes of marriage in America. That’s because a large minority of the rising generation is left leaning, especially young women, and because many of our most important cultural and political leaders are as well.”

“Indeed,” they continue, “a big reason that the Democratic Party has backed away from the institution of marriage is that many of its most devoted supporters are single, left-leaning women. Another reason is that marriage and family life are increasingly coded as Republican issues.”

“This is a bit of a chicken and egg situation,” Family Research Council Senior Fellow Joseph Backholm told The Washington Stand. “The highest values on the Left today are short-term comfort and self-determination. These are not compatible with marriage, which requires a decision to put someone else’s interests above your own, forever, and to sacrifice your own happiness and desires for the good of the whole. So it makes sense that marriage rates would be different based on what you think is most important in life.”

“It’s also true that when you get married, and especially when you have children, your values change,” he continued. “This is part of the reason single women vote differently than married women — and especially married women with children. So I think marriage changes you, but the values you have also determine your likelihood to ever get married.”