If you're running for office against Donald Trump, you can count on this, it seems: he will raise doubts about your faith.
Trump questioned the religious conviction of at least three Republican critics and rivals during the GOP primary over the past year - several times during interviews with "Face the Nation." And this week, as he pivots to the general election, he's back at it, sowing suspicions about the Christianity of presumptive Democratic nominee Hillary Clinton.
"She's been in the public eye for years and years, and yet there's no -- there's nothing out there. There's like nothing out there," Trump said of Clinton's faith during a meeting with Christian leaders this week. A video of the meeting was tweeted by E.W. Jackson, a conservative minister who was present.
Trump warned the leaders at the meeting, "We can't be, again, politically correct, and say 'we pray for all of our leaders' because all of your leaders are selling Christianity down the tubes, selling the evangelicals down the tubes."
Trump later told "CBS This Morning" co-host Norah O'Donnell he didn't mean the remark "in a negative way," adding, "But, you know, I've watched Hillary for a long time. I just don't know anything about her faith. I wouldn't question her faith, but somebody said to me, what do you think? And I said don't know anything about it."
Clinton, for what it's worth, is a Methodist, and she's spoken repeatedly of her faith during this campaign and previously. When she was asked by an Iowa voter in January how her Christianity squares with her politics, she reflected on how her religion has shaped her approach to public life.
"Thank you for asking that. I am a person of faith. I am a Christian. I am a Methodist. I have been raised Methodist. I feel very grateful for the instructions and support I received starting in my family but through my church," she responded, according to the New York Times. "My study of the Bible, my many conversations with people of faith, has led me to believe the most important commandment is to love the Lord with all your might and to love your neighbor as yourself, and that is what I think we are commanded by Christ to do...there is so much more in the Bible about taking care of the poor, visiting the prisoners, taking in the stranger, creating opportunities for others to be lifted up, to find faith themselves, that I think there are many different ways of exercising your faith."
Before Clinton, the most recent target of Trump's innuendo was Mitt Romney, the 2012 GOP nominee who's harshly criticized Trump and refused to endorse him.
"I have many friends that live in Salt Lake City - and by the way, Mitt Romney is not one of them," Trump told an audience in Salt Lake City in March ahead of the Utah primary. "Are you sure he's Mormon? Are we sure?"
Trump later insisted he was only joking.
Last October, when Trump saw his standing in primary polls threatened by retired neurosurgeon Ben Carson, who identifies as a Seventh Day Adventist, Trump mused out loud about Carson's religion.
"I'm Presbyterian. Boy, that's down the middle of the road, folks, in all fairness," he told a crowd in Jacksonville. "I mean, Seventh-day Adventist, I don't know about. I just don't know about."
In an appearance on "Face the Nation" shortly thereafter, Trump denied that he was trying to raise any eyebrows aboutCarson's faith in order to hurt him with evangelical voters.
TRUMP: I don't know about that. I don't know about what that is. I'm not that familiar with it. I have heard about it, but I'm not that familiar with it. That wasn't meant to be insult, obviously. It's just that I don't know about it.
DICKERSON: OK. So an expression of ignorance, not raising questions about it?
TRUMP: Well, it's a harsh way of putting it, but perhaps I could say it that way, yes, because I just don't know about -- as I said, I don't know about that.
Later in 2015, Trump watched as another rival - Texas Sen. Ted Cruz - crept into the lead in Iowa, buoyed by a strong showing among evangelical Christians. At a campaign event in Iowa in December, Trump once again attempted to sow some doubt on the subject ofCruz's religion.
"Just remember this," he told voters. "You gotta remember, in all fairness, to the best of my knowledge, not too many evangelicals come out of Cuba, OK?"
Cruz's evangelical credentials aren't seriously disputed, of course - his platform and stump speech are rooted firmly in his Christian faith. His father, Rafael, is a pastor.
Asked about his quip on Cruz and evangelicals during an appearance on "Face the Nation," Trump once again said he meant nothing by it.
DICKERSON: When you say about Senator Cruz not too many evangelicals come out of the Cuba, what does that mean?
TRUMP: Well, it just means that Cuba, generally speaking, is a Catholic country. And you don't equate evangelicals with Cuba. I don't. I think of evangelicals, and I have a -- I guess I am. I'm Presbyterian. I'm Protestant. But I don't see it as coming out of Cuba.
DICKERSON: But you're not questioning whether -- as far as you know, he could be more devout than you are.
TRUMP: It's possible. Certainly, it's possible. I'm not questioning. And I say it in a somewhat smiling manner, but there's a little truth to it.
Trump also questioned Cruz's faith more directly during the South Carolina primary, asking, "How can Ted Cruz be an Evangelical Christian when he lies so much and is so dishonest?"
Trump, for his part, has bristled at any skepticism about his own religious conviction. After Pope Francis suggested Trump's proposal to build a wall along the U.S.-Mexico border was not something a Christian would propose, the GOP candidate took great umbrage.
"No leader, especially a religious leader, should have the right to question another man's religion or faith," Trump declared on Twitter.
When asked on Face the Nation how he could be upset about the Pope questioning his faith, after he so recently questioned Cruz's religion, Trump said, "No, I never questioned Ted's--anything having to do with his religion...I just said you can't lie and hold up a Bible and you can't do that, you just can't do that, it's not appropriate."