A day before the Brexit referendum, two-thirds of Americans weren't aware it was on the horizon.
So the morning after was a jolt, not for just for Americans watching the markets tumble, wondering about the impact on their savings and pensions but also for liberal pundits and policy makers who are now fretting that the nationalist, isolationist populism that drove the Leave campaign can strike again in the US and bring Donald Trump to the White House.
So, should the presumptive Democratic nominee Hillary Clinton be worried?
Within a few hours of the Brexit results on Friday, two of her senior aides were on the phone with reporters sounding sanguine and confident but also keen to underline that if they Remain camp had underestimated the working class frustration, Clinton had heard it loud and clear on the trail in the US.
Her message according to the aides was: "I hear you, I feel you, I will fight for you."
But their key argument was that American voters will look across the pond at the uncertainty caused by the referendum and think twice about electing a businessman with too many bankruptcies and no political experience like Donald Trump.
In her stump speeches Mrs. Clinton often cites an Economist Intelligence Unit global risk analysis that lists a Trump presidency in the top 10 risks to the global economy, ahead of terrorism.
But the idea that in the quiet of the voting booth, voters will opt for stability over the unknown is precisely what drove the expectation that the Remain camp would win.