Secession will never happen unless or until the government does something so outrageous that there's no walking it back. I'm talking they start going door to door stealing everybody's guns and murdering people. Which will never happen either. At least not on a large scale.
Logistically it's too difficult to accomplish as well. So the Blue States of America or whatever you call them would be the West Coast states, plus Illinois, Michigan, etc. and the upper East Coast? And the rest would be the Red States of America? Those are your countries? Divided up like an old checkers board?
And what about all the Democrats in red states and Republicans in blue states? They're going to keep voting the way they always do unless you plan on shipping them out to the other country. Some would leave voluntarily but most wouldn't have the money or desire to, why else haven't they left already?
The biggest reason it'll never happen is it's only the lunatic fringe who can't get along with the other side. Most people have friends and family who vote for the other side and they get along fine.
Talking about secession is like a hipster thing. You're just trying to make yourself seem smart.