I don’t think there was anything Romney could have done except to promise freebies to every minority out there.
Mittens could have taken the gloves off and hit Obama hard in each debate about Fast and Furious and Benghazi, and set him back on his heels, responding to charges and defending his failed and/or murderous policies.
Instead, he listened to his GOPe advisors, who counseled going the soft old nice-guy Mitt route.
Nice guys finish last, at least when you leave your best weapons on the shelf unused.