269 being, most likely, all they need since a tie would be settled in the House–and if they are losing the House, they are not coming within sniffing distance of 269 anyway.
I am comforted by looking at various scenarios, because they strike me as pretty tough sledding even if they had a good nominee (which looks unlikely). But if they did manage to eke out a win, it seems to me it would be by getting all the Romney states plus Florida, Virginia, Ohio, and Iowa. They might substitute Colorado or Nevada for Iowa, but Iowa seems to me like it would tip before the other two.
(Apologies if this thread has been done before, as I figured it might have been; but I searched and couldn’t find anything.)