If it becomes a State? Yes.
Making all of Canada one State is a mistake. It would create a new California with the exact same problems. Half of California absolutely hates the other half. For the exact same reason half of Canada hates the other half. If Canada becomes one state, that would be two Democratic party Senators and 50 members of the House, along with a California tier weight in the Presidential electoral college.
Fuck no. The Prairies would get two Senators each to counter balance the inevitability of Ontario and BC's Senators while the House caucus will be more uniform and respondant to regional concerns. People forget that for as liberal as California is, a good chunk of its House delegation is Republican. Same goes for shit holes like Oregon, Washington and New York.
The thing is, if the ask is to bring Canada into the Union, it can't be "pick and choose". It needs to be all or nothing, otherwise what is the point. If America isn't willing to incorporate the Canadians, all of them, as fellow citizens, then its better for both that the entire idea be abandoned.