Sen. Robert P. Casey Jr. (D., Pa.) made a whistle-stop plea Monday for Congress to block efforts to cut Amtrak funding 31 percent.
Casey said $350 million in cuts proposed by House Republicans would cost Amtrak workers their jobs and Amtrak passengers their rides.
With Amtrak ridership at record levels, Casey said, "it would be a mistake to adopt the House number."
The Senate and House appropriations committees last month approved very different budgets for Amtrak for the fiscal year that starts Oct. 1: the House, $950 million, and the Senate, $1.45 billion.
Amtrak's current federal subsidy is $1.38 billion.
The fight over Amtrak funding is an annual battle in Congress, with many Republicans seeking to slash or eliminate subsidies for the national railroad, while Democrats (often joined by northeastern Republicans) argue for maintaining or increasing subsidies.
Amtrak has enjoyed growing ridership for more than a decade, and it set a record in 2012 with 31.2 million passengers, up from 21.7 million in 2002.
At the same time, Amtrak's operating subsidy from the federal government has declined, to $466 million this year, down from a peak of $755 million in 2004.
But Amtrak officials say they need much more in non-operating subsidies, to repair and replace old bridges, tunnels, and vehicles.
Amtrak president Joseph Boardman told a Senate committee earlier this year that the railroad faces a "crisis of success," unable to keep up with the growing demand for service, especially on the Northeast Corridor between Washington and Boston.
"We've used up the legacy capacity of the existing railroad while further depleting its infrastructure assets, leading us to a major coming investment crisis that, without a solution, will mean strangled growth and deteriorating service," Boardman said.
House Republican leaders argue that Amtrak receives more subsidy than it needs and that money-losing long-distance routes wipe out an operating profit made on the Northeast Corridor.
And the House Appropriations Committee was especially critical of subsidized meal service on Amtrak trains, saying the railroad had lost $239 million on food and drink service over the past three years.
In Pennsylvania, Amtrak employs 2,986 people, with a payroll of $192 million.
Meeting with reporters at 30th Street Station on his way to Washington, Casey made public a letter he sent Monday to Senate leaders warning that the House cuts would "endanger service on the Northeast Corridor, which serves over 11 million passengers per year, and the Keystone Corridor, (the Philadelphia to Pittsburgh route), which serves over 1.4 million passengers a year."
"Amtrak rail service along the corridor is crucial to the long-term economic competitiveness of the region," Casey wrote.