As I read it the Ford campaign heavily targeted the West. Fords son was in the rodeo and campaigned for his father in states like Arizona, Nevada, Montana, Idaho, Washington etc. Betty Ford was sent to California on her own and was quite popular nationwide. This in addition to the entire west tending to favor the GOP in those days. Fords target to victory was the midwest and west while Carter targeted the East and South. Thus we see a tight electoral college and popular vote.
His son campaigned for him in Idaho and Arizona? Those were safe for the GOP.