WASHINGTON — The messages clog their offices’ phone lines and inboxes by the thousands, each a snapshot of someone’s lived nightmare — the wife whose husband is on a ventilator and getting worse by the day, the small-business owner who desperately needs a loan, the paramedic who wants disinfectant to clean his ambulance between shuttling the ill to the hospital.

They are all punctuated by a flickering hope of a question: Could the congressman help?

Assisting constituents in need has always been a critical part of the job of a member of Congress, but it has perhaps never been as important, or in demand, as it is now. As the coronavirus pandemic rips across the country, lawmakers have been inundated by messages from panicked and suffering Americans searching for a lifeline.

Sidelined from their usual tasks on Capitol Hill, where Congress has been on an extended recess with only brief interruptions to approve huge infusions of federal funding to confront the public health and economic catastrophe, lawmakers are watching their jobs transform before their eyes. There is little for them to do in Washington — no hearings to attend, legislation to debate, or flesh-pressing at fund-raisers — but back home in their districts, they have become de facto case workers, and the needs are more than they can meet.

“The last couple of weeks have fundamentally redefined what my job is, what it means to be a representative,” said Representative Andy Kim, Democrat of New Jersey, whose district, stretching across the eastern suburbs of Philadelphia to the Jersey Shore, has been hit hard by the virus.