A candidate for president promises to reform the country’s healthcare system. Public polling indicates that most voters agree that the system needs reform. The candidate wins by a significant margin and claims a mandate to pursue this reform. Yet no significant changes to the healthcare system occur during the president’s term. The president then seeks reelection despite having failed to achieve the main campaign promise. Which of the following arguments could the president credibly make to the public to best explain this failure?

The healthcare system did not really need reform after all.
Congress refused to take action on the president’s call for reform.
Members of the president’s cabinet were opposed to the plans for reform.
The Supreme Court advised the president that the reforms were unconstitutional.