The fatal train derailment Tuesday night on the line that is the crown jewel of the Amtrak system gave some lawmakers on Capitol Hill a fresh opportunity to attack what they see as dangerously insufficient federal support for the beleaguered railroad.

But, at least in the early stages, the tragedy in Philadelphia seems to be having little effect on the long-running political debate over government funding of Amtrak.

The last year Congress passed a bill authorizing passenger rail programs was 2008, in the waning days of the George W. Bush administration. Democrats wanted to double Amtrak’s budget. The White House wanted to zero it out.

But that September, when a passenger train and a freight train collided in Los Angeles, killing 25 people, lawmakers found new urgency. They stressed the need for a rail safety measure, linked it to the broader Amtrak bill and cleared it for the president’s desk within weeks. Bush, who had once threatened to veto the Amtrak bill, signed the new measure into law, authorizing more money for the rail system.

On Wednesday, within hours of the Philadelphia crash, House ­appropriators voted to slash Amtrak’s budget by 18 percent, while debating a transportation spending bill. There were no immediate plans for the Senate to take up an Amtrak reauthorization bill passed by the House in March.

“Confronting the safety issue is what we are focused on here with this terrible accident,” Sen. Bill Nelson (D-Fla.) said on the Senate floor. “Our heart goes out to the victims. But, at the same time, we’ve got to look to the future, and we’ve got to get our . . . collective heads out of the sand and start producing the funding for infrastructure investment.”

In the House Appropriations Committee, Democrats, citing the crash, tried twice to offer amendments to double Amtrak’s existing funding. Rep. Mike Simpson (R-Idaho) accused them of politicizing the derailment.

“You have no idea what caused this accident,” Simpson said. “Don’t use this tragedy in that way — it was beneath you.”

Preliminary reports suggest that the train was traveling at more than 100 mph, more than twice the speed limit, at the time of the crash.

Meanwhile, the Senate Commerce Committee had intended to introduce its version of an Amtrak bill Wednesday, but pulled back because of the tragedy, said Sen. Cory Booker (D-N.J.).

He said the senators would “take this opportunity to evaluate what other actions might need to be taken as part of the legislation.”

Tuesday night’s derailment comes in the middle of the latest congressional debate over funding for Amtrak. Many members of Congress, particularly those from areas that have little or no Amtrak service, have bridled over the roughly $1 billion-a-year funding for Amtrak’s operations and capital projects.

Investigators combed the Philadelphia site where a New York-bound Amtrak train derailed after leaving D.C.

The House bill approved in committee Wednesday would reduce Amtrak’s funding from $1.4 billion last year to $1.13 billion.

Still, Amtrak has long been a political punch line for fiscal conservatives.

“Of course on Amtrak they lose money on the snack car. They literally have a captive audience. It’s an incredible feat,” former Florida governor Jeb Bush told an audience in Detroit in February.

The nation’s premier passenger rail line has been under fire almost since its inception in 1971. It came into being on unsteady footing, a desperate federal effort to keep passenger rail service alive in an era when cars offered the benefit of door-to-door travel on short distances and airplanes delivered people more swiftly on longer trips.

As passenger numbers dwindled and the equipment and the condition of the rails deteriorated, the big commercial rail lines — the Pennsylvania Railroad and the New York Central, the East Coast titans — faltered and collapsed. At its inception, Amtrak was molded out of 20 passenger operations that had been part of 26 big railroads.

Amtrak began operations in a deep hole, saddled with outdated engines and cars near the end of their useful lives and stations that also had fallen into disrepair. In addition, most of the lines on which their trains operated were owned and maintained by freight railroads that shared them.

Congress later stepped in to transfer portions of the Northeast Corridor to Amtrak control. That section between Washington and Boston became the heart of the Amtrak system.

But the system and its operation of the Northeast Corridor regularly have come under fire from members of Congress who argue the federal government does not need to prop up the for-profit company.

Some Republicans have suggested that the marginally profitable Northeast Corridor should be split off from Amtrak and put in the hands of a private corporation. Others have proposed that the entire system be privatized.

But rail advocates argue that businesses will not invest in something that is not profitable, and point to countries that invest in passenger rail not because it makes money but because the service is good for the community. They look at sleek high-speed trains in Europe and Asia with envy.

American ridership has increased markedly in the past decade. Some attribute it to millennials not sharing the same affinity for the automobile as previous generations. But often generational shifts happen first, and policy catches up.

“I think we have a slow process going in the right direction,” said Ross Capon, who for 40 years ran the National Association of Railroad Passengers. “The ridership has set records, growing substantially while the politicians fight over whether [Amtrak] should exist.”

Kelsey Snell contributed to this report.