Rep. Charlie Melancon, a Democrat from the southern Louisiana coast, pirated a tugboat to reach one of the many isolated communities that he represents. Rep. William J. Jefferson (D-La.), who represents flooded and abandoned New Orleans, sent a staffer to Houston to help constituents living in the Astrodome.

Rep. Bobby Jindal, a Republican and former management consultant, is airing a statewide television advertisement so residents of his suburban New Orleans district know how to reach him. And Rep. Gene Taylor, a Democrat whose Mississippi Gulf Coast home was destroyed, added links to his Web site to inform constituents of road closings and to help them track down their loved ones and their Social Security checks.

For low-profile House members operating on the periphery of the rescue and recovery effort, the aftermath of Hurricane Katrina is posing monumental challenges. Their districts have been reduced to toxic wastelands and swamps, and their constituents have been dispersed throughout the region and beyond. There's no precedent for what these lawmakers and their constituents face, and so the House members are improvising as they go along, based on needs and on their own political instincts.

For them, the crisis poses troubling political questions: What happens to their districts if many of their constituents don't return? How do they stay in touch with their constituents? And how do they squeeze into a spotlight already crowded with senators and governors and administration officials? Their fate is as unpredictable as that of the region they represent.

Whatever the outcome, there is a possibility that by the end of the decade, Louisiana's political boundaries may have to be altered significantly, unless everyone moves back to where they came from.

None of the four is considered a mover and shaker. Jindal and Melancon are Washington neophytes, having won their seats last year. Jefferson is an eight-term veteran who is under federal scrutiny for questionable business dealings as part of a government sting operation. Taylor, a maverick Democrat, is easily overshadowed by his state's powerful Republican senators, Appropriations Committee Chairman Thad Cochran and former majority leader Trent Lott, who used to represent Taylor's district.

"For all these congressmen, it's an opportunity to step up and show your relevance in people's lives," said John Maginnis, a Louisiana political analyst who publishes a weekly newsletter. On the other hand, he added, "they're not line officers, so there's a limit to what they can really do."

Melancon and his staff are taking a hands-on approach. The congressman, a former sugar industry official, has scarcely left his coastal district, large swaths of which suffered extensive damage.

Shortly after the hurricane struck on Aug. 29, Melancon became so frustrated with the federal response that he decided to head out on his own to assess the damage and figure out what people needed. Last Saturday, he navigated his way into Belle Chase, La., to identify how many people were there, how much food they had, and whether they needed medical supplies or gas for generators. He spent about three hours there. While he was leaving, he said, he passed a white Federal Emergency Management Agency car that was heading into town for the first time.

Another of his big concerns is the damaged bridge to Grand Isle, La., which is the only road in and out of the area. To repair the town's broken water lines and address many other problems, the bridge has to be fixed. Melancon is helping local officials get a crew on the job as soon as possible. Another recent intervention: When 200 global positioning devices for emergency vehicles were lost in a Memphis Federal Express warehouse, a Melancon aide called the Tennessee governor's office for help in tracking them down.

Melancon spent six hours in Washington on Thursday, to speak on the House floor and then vote to pass a $51.8 billion emergency aid package, but otherwise, he says, he's staying put in southern Louisiana. "I kind of thrive on it, because it's something that I can do, and it's a way I can help," he said.

The worst political damage could be felt by Jefferson, depending on how radically New Orleans changes as it rises anew. "My guess is there will be fewer black people in New Orleans," Maginnis said.

Jefferson spends his days in Baton Rouge and Washington, in a blur of meetings and briefings and disaster tours, by helicopter, amphibious vehicle and Air Force One with President Bush. He says his main focus is on rebuilding his devastated city. Jefferson estimates that about $100 billion will be needed to "clean up, reconstruct, resettle and revive" New Orleans. Conservative Republicans blanched when Jefferson offered that figure on the House floor, just before the chamber voted on the emergency aid package.

"I want to sound the alarm today," Jefferson said, "lest the House become the victim of hurricane recovery fatigue."

It is an unusual scene these days in the congressman's Washington office, a disaster-relief clearinghouse teeming with staffers and volunteers trying to evacuate constituents who hold the key to Jefferson's political future. Desperate residents plead for help in locating the missing and rescuing the stranded. Staff members fill out a special emergency form for every request. It includes categories such as "trapped in house" and "medical emergency."

A caller on Monday wanted help retrieving seven dogs from a roof, so that their owner would leave, too. On Tuesday, a man reported that 400 Xavier University of Louisiana students were stuck in their dormitory. One woman called Wednesday seeking help for a wheelchair-bound man with congenital heart disease who had been left alone in his house.

In every cubicle in the cramped office, staffers try to pull off miracles from hundreds of miles away. Communications director Melanie Roussell fielded a call from a New Orleans police officer's wife who had relocated to northern Mississippi. The woman had seen her husband crying while being interviewed on television and panicked, having heard accounts that some officers were committing suicide.

Roussell is still trying to locate the woman's husband, but she did resolve the caller's other problem: The woman's diabetic mother was running out of insulin. Roussell secured a supply through a nurse friend who lives in nearby Memphis.

Rep. William J. Jefferson (D-La.) sent a staffer to Houston.