You can be forceful without being mean or bitter; Romney was too moderate in tone. Big Bird was the perfect example. He should have simply said repeatedly that Big Bird can stand on his own two feet, as can most who are instead feeding from the government trough.
But I can't say we had any better options. Why would any sane person run as a Republican, when they can portray a good and decent man like Mitt as some sort of fascist Neanderthal? Young single women feared Mitt would take away their birth control? Seriously? Anyone dumb enough to believe that is not capable of being rationally persuaded.