 Christie said he would "crack down" on states that have ended the prohibition of cannabis if he were president.Christie responded to calls by President Obama to prevent the spread of measles by saying that parents should have a choice.The governor's office said that he "believes vaccines are an important public health protection and with a disease like measles there is no question kids should be vaccinated", but that he was unaware of a free national program to provide new parents with a vaccine checklist.