Why the liberator assumption failed in Canada

Why did American leaders expect an invasion of Canada to succeed during the War of 1812 if Britain could turn back after peace in Europe?

They expected to be received as liberators, but many people in Canada were Loyalists or descendants of factions that had left the United States and had little reason to welcome an American invasion.

The American calculation rested partly on the hope that France might defeat Britain before Britain could concentrate on North America. It also assumed a Canadian welcome that never came. The American Revolution is described here partly as an internal struggle among colonial factions, with some people who lost power or opposed independence moving north. Their descendants were among those resisting the later invasion. An invasion framed as liberation could therefore encounter communities whose own political memory pointed in the opposite direction.