If you had debt while living in Canada then moved to the states can that Canadian debt be enforced in the US?

Sure. The debt is yours, the obligation to pay yours...where you are doesn't change that. Or are you suggesting that as long as we aren't in the country we live in we don't have to pay any bills because nothing can be done about them.

As not paying your debts is probably against the law in Canada, and you can be summoned to court over it, you can be deported for having outstanding warrents, etc. too.