Close the Paoli/Thorndale line? Many say SEPTA is using the threat as leverage.

You hear it from commuters, at “fund SEPTA” rallies, at public hearings and authority board meetings, on Reddit and other social media:

It’s just a political ploy. No way could they shut down the Paoli/Thorndale line.

SEPTA, the theory goes, chose five Regional Rail lines for possible closure to pressure Gov. Josh Shapiro and state legislators for more state money for financially stressed transit systems.

The real reason is more banal, the transit agency says. SEPTA pays Amtrak —$65 million this year — to run the five marked Regional Rail trains on Northeast Corridor tracks owned by the national passenger railroad.

“We looked at the quickest way to save the most money,” said Jody Holton, SEPTA’s chief planning and strategy officer.

SEPTA is running a $213 million structural operating deficit and, in planning its budget for the fiscal year beginning July 1, officials identified service cuts that would get them close to filling the gap.

All told, SEPTA would reduce its service by 45% by running fewer trains, buses, and trolleys and by eliminating some bus routes.

That includes the five rail lines that could be closed in January if state budget negotiations do not produce new aid for SEPTA and transit systems across Pennsylvania.

They are: Paoli/Thorndale, Trenton, Wilmington/Newark, Chestnut Hill West, and Cynwyd.

Many people have said they believe — or at least ask whether — the Paoli/Thorndale line was chosen because it runs through the Main Line. The idea: Some affluent and political influential people live there and ride the line; more than a few probably make political donations, and the governor might accept a personal call from some of them.

Of course, that’s a broad stereotype. Not all Paoli/Thorndale riders, or even Main Liners, are privileged. But the thought’s not out of left field either. Approving the budget is a political process, and pressuring elected officials is just how the sausage gets made sometimes.

Another variant concerns the Chestnut Hill West line. It stops in Chestnut Hill, West Mount Airy, and Germantown, city neighborhoods with histories of organized political activism and protest. The line has its own champion in Save the Train, a coalition of community associations that has 8,000 members.

» READ MORE: These NW Philly neighbors are fighting to protect their Regional Rail line as SEPTA’s budget crisis looms

SEPTA officials say they have heard those and other ideas about the politics of cuts.

“People ask me very strange things like, could you avoid this area or that area?” Holton said. “No. The route keeps going, and it goes everywhere, Geographically, it’s really hard to pull off that kind of political strategy.”

And it could be illegal for a public agency to try.

In 2008, Congress authorized creation of a commission to fairly allocate costs among the eight commuter railroads and several freight lines operating on the 457-mile Northeast Corridor.

The 18-member Northeast Corridor Commission works out the cost-sharing formulas. It includes representatives of Amtrak, the U.S. Department of Transportation, the eight states on the corridor, and the District of Columbia.

“The intent was that there wouldn’t be any cross subsidies,” Holton said, “so that commuter rail was paying its fair share, Amtrak services are paying their fair share, and so forth. It’s quite complicated.”

For instance, SEPTA and the other users pay a proportional share of maintenance costs for wear and tear on tracks and signals and other infrastructure.

Overall, SEPTA’s Regional Rail network runs on 582 miles of track. The five lines that could be closed run on 268 miles of track, or 46% of the total, owned by Amtrak

The Paoli/Thorndale runs along the same track as Amtrak’s Keystone service, which is part of the Northeast Corridor system.

The Trenton Regional Rail trains use Amtrak’s main Northeast Corridor track, as does SEPTA’s Wilmington/Newark commuter line.

Chestnut Hill West uses power generated by Amtrak and the Cynwyd line uses a small bit of Amtrak-owned track, Holton said.

Gov. Josh Shapiro wants to send an additional $292 million yearly in sales tax revenue to transit agencies in Pennsylvania to fund operations.

But state Senate Republicans, who hold the balance of power in the divided legislature, have said they would agree to spend more on transit but would prefer to use a new revenue source rather than the general sales tax. They also want more for roads and bridges.

As the state’s largest transit system, SEPTA grabs outsize attention, but other agencies across the commonwealth are in fiscal danger as well.

Pittsburgh Regional Transit, for instance, faces a $100 million deficit, proportionally larger than SEPTA’s, and plans to cut service by 35% and raise fares by 9% absent state help.

LANTA, the bus system serving the fast-growing Lehigh Valley, has budgeted for a 20% cut in its fixed-route bus service and a 25% fare increase. It projects an $8 million operating deficit.

Public transit agencies across the U.S. have been hit with decreased ridership due to changing post-pandemic commutes, the end of federal pandemic aid that kept systems operating, and escalating costs.

If it does not get more state money, SEPTA would begin to cut about half its service beginning in August.

First, dozens of bus routes would be eliminated, and trips on all rail services would be reduced beginning in late August. Fares would rise 21.5% Sept. 1.

» READ MORE: Is my bus route getting cut? A quick guide to what SEPTA’s proposed changes could mean for you

Next January, the five Regional Rail lines would be eliminated, along with more bus routes (50 in total). All train service would end at 9 p.m.

SEPTA staggered its potential cuts so that some of them might be avoided, depending on when (and if) the legislature acts. Officials say they have no choice but to prepare to wind down service.