In an interviewon HBO on Sunday night, Indiana mayor and presidential candidatePete Buttigiegsaid he will likely not be America’s first gay commander-in-chief if he is elected next year.

But, while appearing onAxios on HBO, he demurred on speculating about who, specifically.

“My gaydar doesn’t even work that well in the present, let alone retroactively,” said Buttigieg, 37. “But one can only assume that’s the case.”

The mayor of South Bend, who has transformed from little-known politician to one of theleading contenders for the Democratic presidential nomination, was responding to a question about how he might combat criticism from conservatives that he is too young, too liberal and too gay.

Statistics about how many people in America identify as gay, or more broadly as LGBTQ, have ranged over the years.

However, there are inherent problems in surveying the LGBTQ community, given the discrimination they face and their reluctance to publicly identify themselves. What’s more, not every LGBTQ American agrees on the use of the same set of identifiers, such as gay or queer.

During his Sunday interview onAxios on HBO, Buttigieg said, “Statistically, it’s almost certain” one of the previous 45 presidents was gay. (Elsewherein the episode, he discussed PresidentDonald Trump‘s handling of the southern border and the Middle East, among other issues.)

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Pete Buttigieg

Curiosity and debate about the possibility of a gay former president is nothing new, with much of the discussion centering on James Buchanan and Abraham Lincoln. Both men had emotionally and physically close relationships with men, though whether either experienced same-sex attraction is in dispute.

Buchanan, a one-term president on the eve of the Civil War, was a notorious bachelor. Lincoln had four children with wife Mary Todd Lincoln.

AsTIME detailed earlier this week, modern discussions of gender and sexualityare more complicated when applied to historical figures— not because same-sex attraction did not exist throughout history but because descriptions of sexual identity and the customs about same-sex behavior have changed drastically over the centuries.

“If what [Buttigieg’s] remarks were that it’s likely that … someone in the past probably experienced same-sex desire, or same-sex attraction, or same-sex encounters, I would say yeah, I would agree with him,” history professor Rachel Cleves told TIME.

“In some ways, the first half of the 19th century was much more open toward physical touch between men and expressions of love,” Cleves said. “Did James Buchanan or Abraham Lincoln identify as ‘gay’ in the modern sense of the term? That would be very difficult. But did they have longstanding relations with other men? In both cases I think the answer is yes, they had deeply loving and physically intimate — although I don’t know that they were sexual — relationships with other men.”

source: people.com