To mark Christmas-Eve-Eve, here's our look earlier this week at how the president-elect has gone all-in on Yuletide messaging -- and the likely reasons why.

As I was preparing to write about the role of religion in President-elect Donald Trump's victory, I got an email in my inbox.

“Make sure your Christmas is Big League this year, Lucy!," Trump's campaign wrote to my dog, who receives our household's political campaign solicitations. “Complete your Christmas list right now with a gift celebrating the 45th President of the United States — Donald J. Trump.”

This is not the campaign's first Christmas-related solicitation. Most famously there was the baseball-cap-Christmas-ornament, all brass and red and gold and yours for the low, low cost of $149 a pop.

But Trump knows his audience. Despite Trump's decidedly patchy record of religious observation and his much more detailed record of violating key precepts of conservative Christian thought, Trump was the overwhelming choice of white evangelical voters in the 2016 election. Not only that, but evangelicals supported Trump by a wider margin than any other Republican candidate has enjoyed in the last four elections.

Why? In part because of Hillary Clinton's less-murky embrace of progressive positions that evangelical voters oppose. And in part because Trump said the right things.

During his penultimate “thank you” post-election event, held Friday in Florida, the red-white-and-blue backdrop we expect from Trump was replaced with a red-and-green one: A line of fully decorated Christmas trees. The placard on the lectern was similarly adjusted, with “USA” demoted in favor of a cursive “Merry Christmas.”

Donald J. Trump speaks during a “USA Thank You Tour 2016" event at the Orlando Amphitheater in the Central Florida Fairgrounds in Orlando on Friday, Dec. 16, 2016. (Jabin Botsford/The Washington Post)

Trump's repeated pledge to bring “Merry Christmas” back to the public vernacular ignored the fact that Americans were always more likely to use that expression than “Happy Holidays.” After all, the country is still three-quarters Christian.

It's often businesses that are the ones that use “Happy Holidays,” since they are hoping to appeal to all 100 percent of Americans, including those non-Christians. PRRI asked Americans if they thought it was appropriate for businesses to use the broader term. The result was about split, with 47 percent supporting the more general term and 46 percent opposing it.

But, as you probably expect, that number differed by religion — and party.

There's overlap between evangelical voters and Republicans, as Pew Research noted in February. Members of most nonevangelical denominations tend more frequently to self-report that they're Democratic — particularly nonwhite Protestant faiths.

(The religion that's most staunchly Republican? Mormons — also the usually Republican group that was most likely to balk at Trump's candidacy.)

In 2012, a businessman uses the more inclusive expression “happy holidays.”

There's a lot of interplay here between race, religion and party, as there are in so many political issues. The PRRI question is interesting in part because it frames the “Merry Christmas” question as one of diversity. The question isn't “do you prefer 'Merry Christmas' or 'Happy Holidays' "; it's whether businesses should “use different language out of respect for people of different faiths.”

This mirrors one of the subtexts to the 2016 election: The role of diversity in American culture. White voters, particularly whites without college degrees, strongly favored Trump this year. Some research suggests that the reason working-class white voters backed Trump so heavily was less about education and more about racial and immigrant resentment. Trump's “make America great again” mantra (available on that $149 Christmas ornament) laments how America has changed; part of that unwelcome change to some voters was certainly how America had grown more diverse. It was places where racial and cultural diversification had occurred most quickly that Trump saw clear strength.

“Happy Holidays” is a part of a broader — and often perceived — drift away a cultural focus on whites and Christians. Evangelical voters were likely to back the Republican whoever it was, but Trump's punching the “Merry Christmas” button clearly helped bolster his credentials with this critical voting bloc. It wasn't the most prominent example of his reinforcing the concerns of white Americans during the campaign, but it was a successful one.

Now we just have to see if Trump's outreach to Christian Americans will result in strong sales of T-shirts to place under the tree.