Erasing any doubts that they will wage a protracted, scorched-earth campaign to win a Senate seat in Pennsylvania, Democrats and their allies wasted little time last week highlighting what they see as Sen. Rick Santorum’s (R) hypocrisy on the issue of Amtrak funding.

A group of union leaders fired off a letter to Santorum accusing the Republican of flip-flopping and ignoring the needs of his state by recently voting against restoring more than $1 billion in funding for the national passenger railroad corporation in next year’s budget.

Sensing the potential volatility of the issue, the Senator penned an opinion column in Friday’s Philadelphia Inquirer expressing his support for Amtrak funding.

The March 23 letter was signed by 10 national and local labor leaders, most of whom represent transportation trades.

“Simply put, an Amtrak bankruptcy would be a disaster for Pennsylvania, and your vote brings us a step closer to that,” the leaders wrote.

The letter was in response to Santorum’s vote a week earlier against an amendment that sought to restore $1 billion in operating subsidies to Amtrak. The measure, introduced by Sen. Robert Byrd (D-W.Va.), failed by a vote of 52-46.

President Bush proposed in his fiscal 2007 budget that Amtrak’s federal funding be eliminated and that the rail line be placed in bankruptcy as a prelude to restructuring.

Through a spokesman, Santorum defended his vote and argued that the Byrd amendment would have increased the overall budget and raised taxes, while providing no assurances “that any of that money will go to Amtrak.”

He said he supports continued funding for Amtrak and that he will work to that end through the appropriations process.

“Appropriators determine what programs receive funding during the annual appropriations process,” Santorum said. “I will work, as I do every year through the appropriations process, to support programs of importance to Pennsylvania, such as funding for Amtrak.”

Amtrak service is an essential part of the state’s economy and transportation system. Philadelphia is Amtrak’s third-busiest station and the company employs more than 3,000 workers in the state. Additionally, eight commuter railroads operate on Amtrak-owned or -operated tracks in the Northeast Corridor.

Santorum reinforced his support for Amtrak funding and the rail line’s continued viability in the Inquirer op-ed.

Santorum wrote that keeping the “trains running should be one of Congress’ priorities in the upcoming budget discussion” and that it would be a “grave mistake to cut the federal funds that keep Amtrak operating.”

But the Democratic Senatorial Campaign Committee immediately seized upon Santorum’s statement, issuing a news release Friday accusing the Republican of flip-flopping.

Democrats and labor say Santorum’s vote contradicted comments he made Feb. 27, during an appearance on NBC’s “Meet the Press.”

When pressed on the issue by host Tim Russert, Santorum said he would fight the president to help preserve Amtrak’s federal subsidies.

Santorum is a top Democratic target and his 2006 re-election race is expected to be among the most expensive and closely watched in the country.

Furthermore, his likely Democratic opponent, Pennsylvania Treasurer Bob Casey Jr., has a close relationship with organized labor and is expected to benefit heavily from union support.

The involvement of organized labor in next year’s race is likely to differ greatly from the subdued role it played in Santorum’s 2000 race against then-Rep. Ron Klink (D), who was not considered a close ally of labor.

Even last year when Democrats attempted to aggressively target Sen. Arlen Specter (R-Pa.), the solid backing he received from labor groups (including the state AFL-CIO) helped harpoon their efforts.

But now there appears to be little question that labor unions are poised to put their full weight behind electing a Democrat and toppling Santorum.

“Between Casey and Santorum it’s clear that only one of the two candidates, Bobby Casey, supports working people,” DSCC spokesman Phil Singer said. “In a close race, everything counts. … Labor could provide a decisive edge.”