Canada's population is very close to that of California.
If admitted, Canada would be entitled to 55 electoral votes and 52 Congressional representatives, as well as two senators.
Canada's politics are very liberal--pretty much in line with California's, in fact.
The Republican party would permanently lose control of the House, at least temporarily lose control of the Senate, and lose control of the White House forever.
Maybe this is a pretty good idea after all! Join us, Canadians; help us throw the Turd in prison and the Republican party in the dumpster!