I suppose the best way to handle this sort of situation would be to refuse the search, turn back away from the border, figure out somebody to hold onto your com

I suppose the best way to handle this sort of situation would be to refuse the search, turn back away from the border, figure out somebody to hold onto your computer (mail it to a friend in the US? It would cross customs, but maybe you could hope it wouldn't be randomly searched. Alternatively just copy the drive to the internet, then trash or sell the hardware), then approach the border again without the computer. They cannot turn you away for refusing to let them search a computer if you do not have a computer.