Senator Portman with his son, Will.

Increasingly, politicians on both sides of the aisle have come out in support of same-sex marriage in recent years. Most famously, in 2012 President Barack Obama told ABC News, “I think same-sex couples should be able to get married.” Former Vice President Dick Cheney and Ohio Senator Rob Portman, both prominent Republicans, have notably defied their party’s stance on the issue to come out in favor of legalizing same-sex marriage. For both, the issue is personal: Dick Cheney’s daughter is a lesbian, and Rob Portman’s son is gay.

Cheney and Portman’s changing views following their children’s coming out are examples of the so-called friends and family effect, by which Americans who share close ties with someone who is gay or lesbian are significantly more likely than those who don’t to favor legalizing same-sex marriage. PRRI’s latest report shows this effect is significant across demographic, religious and political lines. Overall, those who have a gay or lesbian family member or close friend are a full 27 points more likely than Americans who don’t to favor same-sex marriage (63 percent v. 36 percent). And with nearly two-thirds (65 percent) of Americans reporting they have a close friend or family member who’s gay or lesbian, a number nearly three times higher than the 22 percent who reported the same back in 1993, this effect could be helping to drive the rapidly growing support for same-sex marriage across the country.

Do you think the friends and family effect has played a role in determining attitudes  about LGBT issues when it comes to the people you know? Let us know in the comments.