Romney was DOA because he was the worst candidate to run against the Obama presidency. The main things the GOP wanted to attack Obama on were the economy and healthcare. Romney's running mate really understood the economy. Unless you talked to him for more than five seconds, in which case you'd realize he knew fuck all about it. And it was stupid as hell for Romney to attack the ACA as a terrible plan and a terrible investment when he literally used that same model successfully in his own state.
I'd say it was the stupidest campaign I've ever seen, but we literally have Trump campaigning to get re-elected so he can fix the problems that he's responsible for. Dude is literally campaigning against himself.