BLAINE, Wash. — This town near the border of Canada is home to only 5,500 residents, but it has about 20 mailbox stores — so many that the town recently banned new ones from being constructed along the main drag. The stores were built on their allure to Canadians, who save in shipping and customs costs by having their waders from L.L. Bean or mock Tiffany lamps from Amazon mailed to the stores, then carry the packages back over the border.

But this year, the packages have slowed. The mailbox stores have quieted. And Canadians say politics and pride are keeping them away.

“For a lot of people, your president is not their favorite, and they’ve chosen to stay home instead,” said Colleen Clark, 48, a Canadian who lives just 10 minutes from the border, and has stopped coming. “The whole Trump idea — the building the wall, the this and the that. Canadians are a bit more open and inclusive, we’re not into building walls.”

Why did the Canadian cross the border? That’s a complex calculation on America’s northern edge from here in Blaine to the tip of Maine because the variables are always in flux, as currency exchange rates, online shopping trends — and now the uncertainties of international politics and national pride — filter into the mix.