Michael Brown, who was FEMA director when Hurricane Katrina hit the Gulf Coast in 2005, urged President Trump to use his "bully pulpit" to help the agency respond swiftly and effectively to Hurricane Harvey as it begins to bear down on Texas.

"Only you, Mr. President, can take the bully pulpit and command your cabinet secretaries, deputy secretaries and undersecretaries to listen to [FEMA] administrator [Brock] Long and give him what he wants when he wants it, without question and without hesitation," Brown wrote.

Brown noted one of the major parallels between Katrina and Harvey is that both hurricanes developed in August, a major vacation time for elected officials and their staffs.

But, the former FEMA director drew a distinction, one that had to do with the relative newness of the Trump administration.

"FEMA will need assistance from the Departments of Defense, Agriculture, Commerce, Energy, Health and Human Services, Housing and Urban Development, Transportation, Interior, Environmental Protection Agency and others," Brown wrote in The Hill.

"Many of those departments and agencies do not have the political appointees to marshal the resources FEMA will need. Now is not the time to debate why many of those offices are vacant. Now is the time to realize they are vacant and step to the plate as Commander-in-Chief and rally your troops."

Brown also warned the president about the bureaucratic "turf wars" that can emerge during a crisis, and how they can hamper the response by the federal government.

Because he was head of FEMA during the response to Katrina, Brown's tenure at the agency was controversial. He was often the point person blamed for the numerous problems that occurred in the response to Hurricane Katrina. However, Brown has defenders, even some among the left who were hostile to the Bush administration, who have said that he was the scapegoat for the Bush administration's failures as it tried to respond to one of the worst natural disasters in U.S. history.