President Trump is again asking Congress to slash federal aid to the nation’s passenger railroad by cutting funding for Amtrak, including its network in the Northeast Corridor, which stretches from Washington to Boston, by more than half.

Trump’s proposed 2021 budget delivered to Congress on Monday includes reductions in funding to the United States’ busiest rail corridor, the Northeast, to $325 million from $700 million. Funding for Amtrak’s long-distance trains would decrease to $611 million from $1.3 billion under the plan, which intends to phase out aid for long-distance service.

The White House’s budget also proposes billions in other transportation cuts, including a 13 percent reduction in discretionary spending on trains, airports, ports and other areas. It also cuts more than $2 billion in highway infrastructure funds and more than $500 million in transit grants.

The White House touts the Amtrak cuts as a route to overhaul the passenger railroad system to provide better service, focusing on the more profitable short-distance intercity routes while ditching the system’s long-distance trains across the contiguous United States.

“Long distance routes continually underperform, suffering from low ridership and large operating losses of roughly half a billion dollars annually,” the White House’s budget documents say. “Simply put, Amtrak trains inadequately serve many rural markets while not serving many growing metropolitan areas at all.”

But the budget proposal received a cold reception from Democratic congressional leaders, nonprofit organizations and labor unions that advocate for passenger rail service. It prompted groups to launch new efforts to push for more rail funding and the preservation of Amtrak’s long-distance network.

Trump’s budgets have repeatedly targeted Amtrak, but if history holds, the proposal has little chance of winning approval from the House.

Rep. Peter A. DeFazio (D-Ore.), chairman of the House Committee on Transportation and Infrastructure, said the budget puts “critical routes at risk” and sends “Amtrak into a downward spiral.”

Sean Jeans-Gail, vice president of the Rail Passengers Association, said the cuts would hit rural areas particularly hard. The long-distance routes provide the only form of passenger train travel in many communities across the contiguous United States, reaching 140 million Americans in 23 states, he said.

“Trump’s base is rural, where Amtrak provides a very essential service that the free market is not going to provide,” Jeans-Gail said. “But his message is: ‘Screw you the rural stations.’ ”

“It would be a huge blow to passenger train [travel] in the United States if this was implemented,” Jeans-Gail said of Trump’s budget. “But we have successfully beaten this in the last three years, and I have a high degree of confidence we will be able to do the same thing this year.”

The Transportation Trades Department, a coalition of 33 labor unions representing transportation workers, said it is joining efforts “in pushing back on this absurd idea."

“Amtrak has become a vital lifeline to home, work, and school for millions of Americans. For some rural communities, Amtrak’s national network is the only public transportation option available,” the group tweeted Tuesday.

The Rail Passengers Association said it expects Congress to once again ignore Trump’s request to slash Amtrak funding but said it will “not take this attack lying down.”

The group is mobilizing a campaign to push back against Trump’s proposal and seek a funding increase for the railroad system. It also plans to use the surface transportation reauthorization process this year to urge Congress to make the existing service map statutory as the minimum required passenger rail service in the network.

“So we don’t have to spend every year arguing about whether it should exist,” Jeans-Gail said. “We should talk about how we can build service out along urban corridors where it makes sense and provide this base level of service in perpetuity.”

The administration has said that Amtrak should focus on improving its Northeast Corridor service, where it serves more densely populated areas between Washington and Boston. But critics say Trump’s stance is hypocritical because his administration has stalled funding on a key infrastructure project along the route that would improve service and facilitate higher-speed trains.

Trump has sparred with Democratic lawmakers over a $13 billion project to rebuild and repair tunnels and bridges in the New York City area.

In budget documents released Monday, the White House said restructuring the Amtrak system could result in better service at a lower cost, “by focusing trains on better-performing routes, while providing robust intercity bus service connections.”

Besides the $936 million in direct grants to Amtrak, the budget includes $550 million in transitional grants for states and Amtrak to begin the restructuring process. The White House said the subsidy to Amtrak’s national network would be significantly reduced over time “as Amtrak is able to right-size its network.”

Amtrak carried a record 32.5 million passengers in fiscal year 2018, with record growth in the Northeast Corridor and state-supported lines. Total operating revenue rose to $3.3 billion, up 3.6 percent from the previous year, the company said. It’s projected that in 2020, the railroad will have positive earnings for the first time in its history.

Its latest ridership report reflects a year-over-year increase of 800,000 passengers, Amtrak’s highest. Ridership for all Northeast Corridor services reached 12.5 million, an increase of 3.3 percent from 2018. State-supported routes saw a 2.4 percent increase, reaching 15.4 million passengers. Amtrak’s 15 long-distance routes carried 4.5 million passengers last year, an increase of less than 1 percent.