More effectively, Biden also was able to take a shot at Trump’s foreign policy ignorance and showcase his success in beating the National Rifle Association. His strongest moment of the night might have been his defense of his age, arguing he has experience (“with it comes wisdom,” he said) and needs no on-the-job training. He said with much justification that he was the only one to get big things done in the past. He was also successful in piling on Sen. Elizabeth Warren (D-Mass.) for being “vague” on taxes to pay for Medicare-for-all and zinging Sanders for supporting a hugely expensive health-care plan.