It's pretty obvious, I think, that limiting US production of petroleum and NG doesn't do anything about DEMAND and usage, it merely shifts production somewhere else.
That "oil" (or bitumen) from Canada is still being shipped and refined even without the XL pipeline, by rail.
It doesn't help climate change unless you reduce the demand side, not supply (though rising prices will attenuate demand some of course).
I'm a bit surprised a carbon tax is not on the table.