There's always a "duh" answer to questions like this. "Thomas Jefferson owned slaves. Well, of course he couldn't be elected today. Duh." But that's too easy. I'm asking a more complicated question: could someone with Jefferson's religious views become president today?
Jefferson was a deist who didn't believe in the divinity of Christ, the Virgin Birth, or any of the miracles of the Bible. Later in life, but starting during his first term in office, he produced his own abridged version of the Bible that all but reduced the New Testament to Jesus's pithy sayings. Imagine a president today doing something like that. Is there any doubt about the level of mockery he would receive? The right would be slamming him as a secular nut, and the left would quietly distance itself from him.
All serious presidential contenders today must be conventionally religious, or at least pretend to be. Of course, the definition of that concept is debatable. Whether a Mormon or a Jew could be elected is still up in the air, though in 2000 a ticket with a Jewish vice presidential candidate won the popular vote. Eric Cantor, who has been mentioned as a possible rising star in the Republican Party, keeps a kosher home and has spoken positively about his faith. Electorally, that is probably good enough. Though he isn't Orthodox like Lieberman, he hasn't said anything that could be perceived as religiously weird. Imagine, however, a Jewish candidate who thought like Mordecai Kaplan, the founder of Reconstructionist Judaism, whose views on Judaism were analogous to Jefferson's views on Christianity. I don't think such a candidate would stand a chance.
Jefferson was in fact denounced by his opponents as an atheist, but it didn't sink him. Why not? I can think of the following possibilities: (1) Jefferson's views weren't quite as unorthodox when he first ran for president; (2) The early American electorate was more tolerant of deism than it is today; (3) His unorthodox views weren't widely known; (4) Even if they were known, it wasn't as easy to circulate them as it would be in an age of mass media.
What is your explanation?