One possibility (perhaps a long shot) would be for the US citizen to move to Canada at first, find a job either with a US company, or for the US government, or for another institution that qualifies, and then for the Canadian spouse to apply for "expeditious naturalization" as a US citize...

I am trying to research this for my friend who is in a strange situation. My friend is a US citizen and marrying a Canadian guy. Now she could sponsor him to come to US, but the problem is that his mother is dependent upon him, and he cares too much to just leave her in Canada. So far the research s...