President Trump says he plans to nominate Kirstjen Nielsen to serve as the next homeland security secretary. John Kelly, Trump’s previous homeland security secretary, now serves as Trump’s chief of staff. Nielsen is a longtime DHS official, recently serving as Kelly’s chief of staff. Under President George W. Bush, she was the senior director for preparedness and response at the White House Security Council ahead of Hurricane Katrina. She was subsequently singled out in congressional reports as one of the key figures in the Bush administration who had been warned about the impending catastrophe of Katrina, but failed to act. She’s also worked in the for-profit security industry, first at a firm called Civitas Group and then founding the security firm Sunesis Consulting.