A year after presiding over a sluggish and chaotic response to a devastating storm in Puerto Rico, the Trump administration girded on Wednesday for a test of its ability to do better as Hurricane Florence continued to bear down on the Carolina coast.

If responding to the destruction from Hurricane Maria last year in Puerto Rico was especially challenging — it was the third major hurricane of the season, it struck off the United States mainland and the local government was often overwhelmed — Florence presents more manageable logistics for the Federal Emergency Management Agency.

It is the first big storm of 2018. FEMA and state and local officials have had days to prepare, and the agency has positioned considerable supplies and personnel in the areas most likely to be affected. Two months before the midterm elections, President Trump has put himself front and center in the government’s response, suggesting that the White House will be fully invested in providing the necessary resources.

Beyond the threat to lives and property, the storm also poses a formidable political challenge for Mr. Trump, whose public posture has been shaped by his penchant for self-congratulation and relish for lashing out at political rivals.

Mr. Trump began his morning on Wednesday doling out A-pluses to his administration for its performance during last year’s hurricane season. He called its response to Hurricane Maria — whose death toll in Puerto Rico was recently estimated at 2,975 — “an unappreciated great job” in a Twitter post that blamed the “inaccessible island with very poor electricity and a totally incompetent Mayor of San Juan” for the devastation there.

Mr. Trump also posted a video of himself in the Rose Garden of the White House in which he vacillated between sober warnings and exhortations to flee the storm’s path, and reassurance bordering on overconfidence.

“Tremendous people working on the hurricane,” Mr. Trump said later at a Congressional Medal of Honor Society reception in the East Room. “First responders, law enforcement and FEMA, and they’re all ready. And we’re getting tremendous accolades from politicians and the people.”

The response to three hurricanes last year — Irma, Harvey and Maria — ignited intense criticism of the administration and FEMA, particularly for their struggles to quickly deliver food and fresh water to storm victims in Puerto Rico and help restore power there.

While various studies have allocated blame for shortcomings in the response to Hurricane Maria to officials in Puerto Rico as well as to the federal government, there is little to support Mr. Trump’s characterization of the response as “great.” In a report released in July, FEMA itself said it vastly underestimated the amount of supplies it would need, and how hard it would be to get additional supplies to the island.

Brock Long, the administrator of the agency and a veteran of emergency management, has said that it learned from its responses to hurricanes last year and would be better prepared to confront disasters.

Emergency management officials in North Carolina said FEMA had positioned water, meals, cots and portable generators at Fort Bragg, an Army base in Fayetteville, N.C.

In addition, officials said other locations in South Carolina and Georgia would be used as support bases to distribute more food, water and other supplies when needed. FEMA search-and-rescues teams are also standing by, officials said.

In April, the agency created a number of FEMA Integration Teams, which are permanently deployed to work with state officials and provide technical and training assistance, according to the agency. North Carolina was the first state to have the teams deployed there.

The planned response to the potential for widespread power outages is also a sharp departure from that employed by Puerto Rico’s government and FEMA after Hurricane Maria.

This time, the government is largely deferring to power companies, which under mutual aid pacts that allow them to draw help from utilities in nearby states are already massing thousands of workers in the region to begin repairs once Hurricane Florence has passed.

Some 20,000 workers are already waiting in hotels, staging areas, and — for those employed locally — in their homes to be called into action once conditions are safe enough, said Neil Nissan, a spokesman for Duke Energy, which has 4 million customers in the Carolinas. And those are just the workers assigned to assist Duke, the largest power company in the Carolinas, said Brian Reil, a spokesman for Edison Electric Institute, an industry group that helps coordinate the mutual aid response. An additional 20,000 workers have been dispatched to other utilities in the area, he said.

Computer modeling indicates that somewhere between one to three million of Duke Energy’s customers will lose power, some for brief periods and others for weeks because of coastal flooding, Mr. Nissan said.

For those reasons, Mr. Nissan said, Duke has been telling its customers that the storm is “a potentially life-changing event.”

Puerto Rico did not immediately invoke mutual aid after Hurricane Maria because the governor said the island did not have aid agreements in place and he believed that the island did not have enough money set aside for initial payments that might be owed to mainland utilities. That decision made the hurricane the only known case in recent history in which mutual aid was not invoked after a major power failure.

But instead of working with Puerto Rico to invoke the aid and deal with any costs later, FEMA took the extraordinary step of asking the United States Army Corps of Engineers to take a leading part in the emergency restoration, a task it had never carried out before.

Puerto Rico compounded the mistake by hiring a small contractor, Whitefish Energy, to carry out many of the tasks that thousands of mutual aid workers would have undertaken under normal circumstances. And the logistics of moving people, equipment and millions of parts to the island helped bog down the effort until it became a slow, frustrating and ultimately disastrous effort to restore power to desperate citizens.

This time, FEMA officials say they are prepared, though they are striking more cautious tones than the president and emphasizing the destructive power of the hurricane.

“This has an opportunity of being a very devastating storm,” Mr. Long said in a presentation in the Oval Office with Mr. Trump on Tuesday, predicting weekslong power shutdowns, mass flooding and people being displaced from their homes.

During a conference call with reporters on Wednesday, officials said that they have employees and supplies in place in North and South Carolina as well as Georgia, the states that are expected to be the hardest hit.

“We have plenty of resources to respond. We have plenty of resources to recover,” said Jeffrey Byard, FEMA’s associate administrator for response and recovery.

Bryan Koon, the former state emergency management director in Florida, said that so far the agency seemed to have everything in place to respond to a hurricane that is expected to dump as much as 40 inches of rain in North Carolina alone.

“They have put things in place and coordinated with state and local officials,” Mr. Koon said. “But I don’t know how this will play out in the actual response itself.”

Since Hurricane Katrina in 2005, the federal response to deadly storms has taken on overt political implications, often standing in for an administration’s competence and empathy.

The timing could not be more consequential for the president and his party. With the midterms approaching and control of the House and the Senate at stake, Mr. Trump’s approval ratings have dropped to 36 percent, according to the latest CNN poll, a potential danger zone for Republican candidates.

As if to underscore the political dimensions of the storm, the Department of Homeland Security offered a carefully worded statement on Wednesday that suggested it would suspend or scale back Mr. Trump’s top priority, the enforcement of immigration laws, in the affected areas while the storm was underway.

“Our highest priority remains the preservation of life and safety,” the department said in response to a question about its policies. “In consideration of these circumstances, there will be no immigration enforcement initiatives associated with evacuations or sheltering related to Florence, except in the event of a serious public safety threat.”

Democrats sought to make a political point as well, castigating the Trump administration for reallocating $10 million from FEMA accounts to Immigration and Customs Enforcement to help detain and remove undocumented immigrants, although the department said the funds in question would never have been available for disaster response.

Natural disasters always carry high stakes for the president, focusing the public’s attention on a core function of government they tend to ignore except when their lives or property are at grave risk. And presidents have learned the hard way — as George W. Bush did after Hurricane Katrina in 2005, when he drew criticism for telling his FEMA director Michael Brown, “Brownie, you’re doing a heck of a job” — to keep to a minimum credit-claiming and praise-heaping.

“It’s Trump’s nature to speak with hyperbole — ‘Great for us, we’re amazing’ — and we saw how that failed George W. Bush, and gave people a real sense that this was a president who did not understand what was happening on the ground and in their lives,” said Douglas Brinkley, a presidential historian whose book “The Great Deluge” chronicled the devastation of Hurricane Katrina and its aftermath.

“There’s no way that the government ever looks good after a natural disaster, because there will always be the sense that more could have been done,” Mr. Brinkley said. “You don’t want to turn disaster into a political victory, but that is Trump’s instinct with everything.”

Tom Bossert, Mr. Trump’s former homeland security adviser, said the president’s bullish statements have not been “politically expedient.” But he added that the president had “changed the rules of political risk analysis,” defying the public’s expectations for what would and would not tarnish a commander in chief.

“My instinct was always to be very somber in advance of a storm like this, because you don’t want to overpromise, and you don’t want to over-reassure,” Mr. Bossert added.

In some ways, he added, the hurricanes offer the worst of both worlds for the administration — a situation that is seen as a federal responsibility but that, in essence, will rise or fall according to whether the specific areas affected can absorb it.

He said the Mid-Atlantic states currently in the storm’s path were better “institutionally prepared” than Puerto Rico had been, which he said was “in absolutely unacceptable disrepair and conditions when that storm hit.”