The question was "Can you enter Canada with a NEXUS card in lieu of a Passport?" The answer is yes.
If the question had been, "can you board a flight from the US to Canada...?" the answers is still yes, however there have been reports of people having issues despite it being allowed. There is at least one other thread discussing this point.
Air Canada's website clearly staes that a NEXUS card is accepted.
https://www.aircanada.com/ca/en/aco/...cuments.html#/