Michelle Obama says Donald Trump can't sweep birtherism under the rug with an 'insincere sentence.'

Stumping for Hillary Clinton on Wednesday, first lady Michelle Obama slammed Donald Trump for what she called his "hurtful" pushing of rumors that her husband was not born in the United States. Obama said Trump could not be forgiven for all he's said with an "insincere sentence uttered at a press conference," claiming he now believes the president was born in America.