Overlooking picturesque Perkins Cove in Ogunquit, southern Maine, Barnacle Billy’s has welcomed presidents, prime ministers and princes over the past six and a half decades.

George HW Bush used to ferry world leaders, including Bill Clinton and Mikhail Gorbachev, on his speedboat across the bay to the seafood restaurant from his summer residence at Walker’s Point.

But now Tim Tower, the owner of the business, is more focused on a more prosaic clientele: Canadians.

Nearly 800,000 Canadians crossed the border last year, spending almost half a billion dollars in the US.

This year, Maine’s businesses are bracing themselves for a 25 per cent drop, largely thanks to Donald Trump.

His repeated suggestions that Canada should become America’s 51st state, coupled with his tariff war, saw the number of tourists crossing over the Canadian border to holiday in the States drop by 157,000 in the first four months of the year.