Patrick S. Roberts is an associate professor in the school of public and international affairs at Virginia Tech and author of “Disasters and the American State: How Politicians, Bureaucrats, and the Public Prepare for the Unexpected.”

President Trump has made the obligatory stops in Texas and Florida after Harvey and Irma. (Nicholas Kamm/AFP/Getty Images)

In the wake of Hurricane Harvey, President Trump made the obligatory trip to Texas to demonstrate his empathy for disaster victims and to show his support for the recovery effort. On Wednesday, the president visited Florida in an effort to demonstrate that he is “a true leader who can bring the country together and get things done for the American people,” according to White House press secretary Sarah Huckabee Sanders.

Although such appearances have become routine, both the role of the president as a “responder-in-chief” and the belief that the federal government will ride to the rescue of disaster victims are a more recent development. Disasters were originally a matter for states and localities, if for the government at all. Today, by contrast, expectations for the president and the federal government have grown. Both have assumed larger roles in any number of policy areas, including education and welfare, over the past 80 years.

But disasters demand something more.

With powerful images that inspire fear and compassion, disasters create victims endowed with sympathy and perceived to be blameless and deserving of assistance. There’s no talk of anyone failing educational achievement tests, or of welfare recipients abusing government aid. And both Democrats and Republicans demand that the federal government help disaster victims.

In this environment, presidents feel called into action, literally rolling up their sleeves and appearing on scene to show compassion for those affected. But these appearances, and the widely circulated images they produce, are acts of political theater. The actual response is led not by the White House, but by neighbors, localities, states and the federal bureaucracy.

This sort of political theater is not without risk. Contrast the praise George W. Bush earned when he appeared alongside first responders after the Sept. 11, 2001, attacks with the sharp criticism of the photo of him surveying the damage from Hurricane Katrina while aboard Air Force One. Bush himself called the photo a “huge mistake” that made him look “detached and uncaring.” But the greater risk may be in heightening American expectations of what the federal government can accomplish without actually providing the resources needed to prevent such catastrophes.

Presidents weren’t always at the center of disaster response. Throughout the 19th century the U.S. government made more than 100 ad hoc appropriations after earthquakes, fires, floods and Indian raids to restore infrastructure, such as ports and canals. Pleas for appropriations were directed at Congress, not the president, and some members objected that the “general welfare” clause of the Constitution was an insufficient basis on which to claim federal authority for disaster response.

After the 1906 San Francisco earthquake killed more than 3,000 people and leveled more than three-quarters of the city, President Theodore Roosevelt sent a telegram to the California governor: “Hear rumors of great disaster through an earthquake at San Francisco, but know nothing of the real facts.” Roosevelt called a Cabinet meeting the next day and sent his commerce secretary to California to investigate. The Red Cross responded on the federal government’s behalf days after the event, but information about what actually happened was scarce.

The New Deal and Great Society expanded the role of the federal government in American life, and disaster policy was no exception. In fact, President Franklin Roosevelt and Solicitor General Stanley Reed argued to the Supreme Court in 1936 that the Depression itself was a disaster that demanded federal intervention. And when floods and hurricanes hit in 1936 and 1937, New Deal agencies administered disaster relief, further justifying their existence.

Presidents also became tethered to disaster politics through a civil defense bureaucracy created to prepare for nuclear war. While civil defenders lost faith that they could save people from nuclear attack, they took pride in preparing for the fires, floods, earthquake, hurricanes and tornadoes that threatened their communities more often than the specter of nuclear war. A bomb shelter might offer little protection from direct nuclear attack, but it could save lives in a tornado.

Along with institutional changes such as the 1974 Disaster Relief Act and the 1988 Stafford Act that gave presidents more authority, both Congress and presidents learned that media coverage of disasters could bring attention and resources that provided electoral benefits.

In one of the earliest examples, Sen. Russell Long of Louisiana urged President Lyndon B. Johnson to visit New Orleans after Hurricane Betsy in 1965 to witness the damage and pose for the media. When Johnson balked, Long retorted, “If you go there right now, Mr. President, they couldn’t beat you if Eisenhower ran!” LBJ went, and he was so concerned about the damage that he demanded daily progress reports on the recovery and promised generous aid from more than 20 federal agencies. He even directed the Air Force to fly engineers to New Orleans to restore the city’s communications.

Expectations of the president and federal government rose so high that by the 1990s, people assumed that the Federal Emergency Management Agency (FEMA) would come to the rescue after a natural disaster. After Hurricane Andrew hit Florida in 1992, the emergency manager of Dade County, Fla., famously asked the media, “Where in the hell is the cavalry?” after her requests for aid from FEMA went unanswered. Some members of Congress wanted to abolish FEMA for not doing enough. Critics blamed the slow response for contributing to President George H.W. Bush’s image as ineffectual and to his loss in the 1992 election.

President Bill Clinton wrote in his autobiography that many presidents give the job of FEMA director to a crony, but he vowed never to make that mistake. He appointed an experienced emergency manager, James Lee Witt, to lead the agency, and to be his “eyes and ears” after a disaster — whether a hurricane, tornado or a plane crash. Like Johnson, Clinton realized he could derive political benefits from being seen as helping disaster victims.

And yet, while disasters make for good electoral politics, what can presidents actually do in a disaster beyond the theater of rolling up their shirt sleeves? They can get out of the way and let the bureaucracy do its job.

This means physically keeping their entourage from interfering with first responders — something Trump did by visiting Corpus Christi rather than Houston, which was still reeling from Harvey. And it also means overseeing the bureaucracy by pressuring agencies to cooperate and share resources. Red tape and parochial concerns slowed some of the response to Katrina, and Bush and FEMA drew some of the blame.

Increasing expectations in the 21st-century media environment have made response and recovery more of a federal government priority than in the past. Now natural disasters are as much a test of a president’s skill as war or the economy.

But the politics of disaster encourage reaction rather than prevention — something that is far less unifying and over which presidents have less power. The root causes of disaster losses are the patterns of human settlement in risky locations: vulnerable development in low-lying coastal and riverfront areas and earthquake zones, which presidents have minimal ability to control.

As such, attributing disaster response to the president distorts how we think about both disasters and government, because, in fact, the bulk of the responsibility for preparation and response occurs at the state and local level. FEMA today is much improved from the FEMA of the Katrina-era, but flood insurance and flood mapping remain as inadequate as ever — making the next disaster more likely than the last.