(CNN) The only Democrat talking at length about his faith in the 2020 primary also happens to be the only gay candidate in the race. And he's one of the few from a red state.

South Bend, Indiana, Mayor Pete Buttigieg is an Episcopalian who can freely quote Bible verses. He's also a presidential candidate who embraces his husband on stage at campaign rallies.

Combining homosexuality and Christianity might be the most natural thing in the world for Buttigieg and millions of gay Americans, but it is an iconoclastic development in American politics, where generalizations about religious freedom have in recent years been used specifically to fight advances in LGBTQ rights.

For some on the religious right, like Franklin Graham, Buttigieg's identity, while it's shared by many gay Americans of faith, does not compute.

Graham, in a series of critical tweets, said that being a gay Christian "is something to be repentant of, not to be flaunted, praised or politicized."

Presidential candidate & South Bend Mayor @PeteButtigieg is right—God doesn't have a political party. But God does have commandments, laws & standards He gives us to live by. God doesn't change. His Word is the same yesterday, today & forever. 1/3 https://t.co/QHDNY3pwzJ

Mayor Buttigieg says he's a gay Christian. As a Christian I believe the Bible which defines homosexuality as sin, something to be repentant of, not something to be flaunted, praised or politicized. The Bible says marriage is between a man & a woman—not two men, not two women. 2/3

The core of the Christian faith is believing and following Jesus Christ, who God sent to be the Savior of the world—to save us from sin, to save us from hell, to save us from eternal damnation. 3/3 — Franklin Graham (@Franklin_Graham) April 24, 2019

Graham's position is ironic and hypocritical given his and the religious right's embrace of Donald Trump as President.

No one should presume to know another person's faith, but it is a statement of fact that Trump is a thrice-married megalomaniac who is certain in his infallibility and has mangled Bible verses when he's tried to read them out loud

But conservative faith leaders have pushed Trump and applauded him in particular for his selection of conservative Supreme Court justices like Neil Gorsuch and Brett Kavanaugh, who they hope will challenge court precedent on abortion and marriage equality.

Buttigieg has poked at this hypocrisy, questioning whether Trump believes in God . He's brought attacks on Vice President Mike Pence, who has joined the fight against gay rights and who wears his faith -- he is an evangelical Christian -- on his sleeve.

JUST WATCHED Buttigieg on Pence: My quarrel is with this ... Replay More Videos ... MUST WATCH Buttigieg on Pence: My quarrel is with this ... 01:37

"I hope that Pete will offer more to the American people than attacks on my Christian faith or attacks on the President as he seeks the highest office in the land," Pence told CNN's Dana Bash after Buttigieg's criticism , later adding, "he'd do well to reflect on the importance of respecting the freedom of religion of every American."

JUST WATCHED Pence says Buttigieg bringing 'attacks' on his faith Replay More Videos ... MUST WATCH Pence says Buttigieg bringing 'attacks' on his faith 01:42

Comments from leaders like Graham, a supporter of Trump who is now saying Buttigieg's interpretation of faith is flawed, will complicate Pence's argument that his own faith is being targeted by Buttigieg.

What drew Graham's ire were comments at a CNN town hall this week, when Buttigieg was asked by a woman who described herself as a bisexual Christian, how he will "challenge the right's moral monopoly on Christianity to unite conservative, moderate and liberal Christians alike..."

His full answer is worth reading, but the essence is that he acknowledged it "can be challenging to be a person of faith who's also part of the LGBTQ community" while also saying his understanding of faith is far different than Pence's or Graham's:

"Part of where I'm coming from is a faith tradition that counsels me to be as humble as possible, that counsels me to look after those who need defending.

And frankly, it couldn't be more radically different than what I see certainly in this White House, where there's a lot of chest-thumping and self-aggrandizing, not to mention abusive behavior, but also a political agenda that seems to always be revolving around the idea that somehow it's too easy for poor people in this country. It's just so different than what I get when I read scripture.

And I get that one of the things about scripture is different people see different things in it. But at the very least, we should be able to establish that God does not have a political party."

There is still a strong religious divide in the country on the subject of gay rights. In a 2017 Pew survey, there was strong support (62%) among all Americans for same-sex marriage like the one a Supreme Court decision allows Buttigieg to enjoy. Just 32% of Americans oppose it.

More than two-thirds of Americans not affiliated with a religion (85%) support it, along with Catholics (67%) and white mainline Protestants (68%). But support was less than 50% among other groups Pew broke out, including black Protestants (44% support) and white evangelical Protestants (35%).

That divide carried over to political groups. Just 40% of Republicans supported same-sex marriage in the survey, compared to 73% of Democrats and 60% of Independents.

There are other polls, such as this one from Pew , that document how Republicans are more likely to believe in God than Democrats, that they're more likely to go to church, and that religion plays a larger role in the lives of more Republicans than Democrats.

Which is not to say that Democrats don't rely on religious voters. But they tend to focus on black churches. Trump, however, is equally or more reliant on white evangelicals to help him win re-election. Pence is not the only evangelical Christian working for the President; his press secretary Sarah Sanders said God wants Trump to be in office

It's not at all clear that Buttigieg would be able to win over more churchgoers than other candidates. Hillary Clinton, a churchgoing Methodist, spoke less often than him about her own faith, but she did talk about it. She lost in 2016, however, among people who go to church monthly or more (Clinton got 43% to Trump's 53%), according to exit polls. She won 54% - 39% among people who go less than that.

The country is changing, however.