Undoing Obama's Executive Actions

Many of the GOP candidates have vowed to dismantle some key legislative and executive actions made by President Obama, such as the Affordable Care Act, immigration reforms, the nuclear deal with Iran, and new regulations designed to slow climate change. How easy is it for a new president to reverse the policies of their predecessor?

Here & Now's Robin Young talks to Julian Zelizer, a professor of history and public affairs at Princeton University a contributor for CNN.com.