Earmarks, the targeted spending projects secretively inserted into larger bills, have made news lately. A growing number of critics are asking why President Barack Obama allowed the Democrat-controlled House of Representatives to include some 8,500 earmarks, amounting to $7.7 billion, in the $410 billion spending bill passed by Congress last week.

Among the earmarks are 13 defense-related spending items co-sponsored by 104 House members and backed by a single lobbying firm, PMA Group.

Democrats in Congress have defeated efforts to remove the PMA-related earmarks. But there are valid reasons to set those spending items aside for further analysis, and to closely review them in light of a federal investigation.

Earmarks in any form should raise questions because the spending, even if justified, received no public scrutiny or discussion in Congress.

But more than any others, earmarks tied to PMA Group should be viewed with even more skepticism, given that PMA offices were raided by federal officials late last year as part of an FBIprobe of PMA's campaign contributions. Investigators believe the lobbying firm has used straw donors to increase its donations to favored politicians.

Coincidentally, not long after the FBIraid, published reports said that PMA would be closing down its lobbying operation, with several principals having already left the firm.

As a lobbying business, PMAhas raised eyebrows for years. It was founded by Paul Magliochetti, a former aide to U.S. Rep. John Murtha, D-Pa. And Murtha's role as the chairman of the House Appropriations Subcommittee, which controls defense spending, the specialty area for PMA Group, does argue for a closer examination of PMA-related spending and contributions.

As a lobbying firm, PMA has been notable for its efficiency and effectiveness. In 2007, the operation brought in $17 million in lobbying revenue, which is a significant figure for a company with only 34 lobbyists

And those lobbyists were very effective when it came to encouraging House members to sign up as co-sponsors of legislation benefiting their defense industry clients. The 2008 defense appropriations law contained earmarks valued at $300 million for PMAclients.

A report from opensecrets.org found that PMA and people connected to its lobbying clients have, since 1998, given $7.8 million to lawmakers on Murtha's committee.

A New York Times editorial last month commented on PMA Group and described the flow of money between defense contractors and the lobbying firm and also to cooperative lawmakers. The Times described the PMA revolving door of money and political influence as a "detailed blueprint of how the political money churn works in Congress."

While urging federal investigators to follow the money trail leading to and from PMA, the Times editorial noted that new disclosure requirements (created after the Jack Abramoff scandal) "reveal the shameless back-scratching of lobbyist and lawmaker, tracking the flow of taxpayers' funds to contractors and back as booty to lawmakers."

The path of money into and out of PMA Group and its client base should tell an interesting and informative story.

"Follow the money" was the simple suggestion from Deep Throat during the Watergate scandal in the early 1970s. And that remains good advice today.