From their perch on the House Appropriations Subcommittee on Defense, three House Democrats have steered $100.5 million to clients of a lobbying firm that is emerging as a top source of their campaign funds.

The lawmakers — Reps. John Murtha (Pa.), Jim Moran (Va.) and Peter Visclosky (Ind.) — used the Defense spending bill to earmark 36 projects to clients of the PMA Group. That represents more than a third of the projects they inserted into the 2008 House Defense appropriations bill, according to an analysis by Roll Call and Taxpayers for Common Sense of records from the Appropriations Committee.

Meanwhile, PMA lobbyists and their clients have been stepping up their fundraising for the three lawmakers, contributing $542,350 in the first six months of this year, or 26 percent of their total fundraising, according to a Roll Call analysis of Federal Election Commission data.

The earmarking boon has proved profitable for the Arlington, Va.-based firm, which collected $2.4 million in the first half of the year from the 24 clients that secured earmarks in the Defense bill, just over a quarter of its total six-month revenues.

Taken together, the hundreds of thousands of dollars in campaign contributions from firm clients to the lawmakers and the millions of dollars in earmarked projects from the lawmakers to the clients paint a vivid picture of mutually beneficial interests at work.

“It’s pretty staggering to look at how much this is,” said Steve Ellis, of vice president of Taxpayers for Common Sense and an earmark critic. “This is the classic Washington iron triangle — lawmaker gets campaign cash, companies get earmarks, lobbyists get rich. You do the math.”

Carmen Jacobs, a lawyer for the PMA Group, called the earmark figures inflated because “some of the clients have different firms working for them.”

“PMA clients have multiple representation by different lobbying firms,” he said.

In fact, nine of the companies that received earmarks from the three Democratic appropriators also employ other lobbying firms, according to Senate filings. Five of those companies have only one other firm on retainer.

Jacobs said the fundraising totals also are misleading because, he said, PMA officials have no control over what clients decide to give. He noted that the firm’s political action committee has only directed $5,000 each to Moran and Visclosky this year, and nothing to Murtha.

“PMA doesn’t know what their clients give to these folks,” he said.

The timing of the contributions, however, suggests a more coordinated dynamic.

On March 28, for example, Visclosky received $79,500 in campaign contributions. Only $4,500 of that came from individuals who do not appear linked to the firm. PMA lobbyists wrote personal checks totaling $27,000. The rest came from officials with five different companies, all clients of PMA.

Spokesmen for the three lawmakers did not respond to requests for comment. Eight PMA clients also did not return calls or declined to discuss their relationship with the firm.

The PMA Group was founded in 1989 by Paul Magliochetti, who had spent the previous decade as Murtha’s right-hand man on the Appropriations Subcommittee on Defense. In the years since opening its doors, the shop steadily has climbed the K Street ranks, emerging as a powerhouse in recent years as it solidified a reputation as the go-to firm for access to Murtha.

With the boom in federal earmarking, Murtha’s position atop the Defense spending panel has made him an increasingly hot commodity for contractors — a phenomenon that in turn has boosted the stock of his inner circle in the lobbying community.

In the first six months of 1998, PMA pulled in $1.4 million, placing it 44th among K Street firms by revenue, according to CQ MoneyLine. By the first half of this year, it had vaulted to the No. 9 spot by earning $8.6 million.

That result is especially notable given the climate for appropriations lobbyists this year. Democrats returned to the majority pledging to pare back earmarks in order to restore the fiscal accountability they charged Republicans with neglecting. Indeed, House appropriators more than halved the cost of earmarks in the Defense bill this year, cutting them to $3 billion from $7.2 billion in 2006, according to figures from Taxpayers for Common Sense.

One appropriations lobbyist said the lean year made PMA’s success at securing earmarks more surprising. “In a year like this, that’s on the high side — unusually high. It’s harder to get earmarks, but you have just as many people asking, if not more.”

The firm has broadened its reach on the Defense spending committee by making strategic hires in recent years. At the end of 2003, Richard Kaelin left his post as Visclosky’s chief of staff to join the firm. Last year, Melissa Koloszar signed up as a PMA lobbyist after a decade in Moran’s office, most recently serving as chief of staff.

At the same time, the firm and its clients steadily intensified their fundraising support for Murtha, Moran and Visclosky. In the 2002 election cycle, PMA and its clients raised $369,675 for Murtha, or 16 percent of his total funds; $88,930 for Moran, or 9 percent of his total funds; and $114,000 for Visclosky, or 12 percent of his total funds, according to an analysis of federal election records.

By the 2006 cycle, those numbers had jumped to $608,049 for Murtha, 20 percent of his total; $274,400 for Moran, 18 percent of his total; and $450,625 for Visclosky, 33 percent of his total.