In a political environment where corporations are actively looking to add blue to their ranks, the departure of Goldman Sachs’ top Democratic lobbyist, Marti Thomas, to the Duberstein Group Inc. is a big hit for the former investment bank, which faces a litany of issues on Capitol Hill.

Thomas, who will join Duberstein in February, was in charge of federal legislative affairs for Goldman and its clients.

Goldman’s other senior Democratic in-house lobbyist, Mark Patterson, left last spring.

Thomas is rejoining the consulting world after a lengthy career both on the Hill and in lobbying. She spent almost all of the 1990s as former House Democratic Leader Dick Gephardt’s (Mo.) top floor assistant.

A two-year stint at the Department of Treasury followed, then six years as a lobbyist at Quinn Gillespie & Associates before moving to Goldman’s D.C. shop in 2007.

“It’s a great addition for us,” said Duberstein Group President Michael Berman. “She’s got great experience on the Hill and in the private sector and we’re just delighted to have an addition of her quality.”

The hire was a rare move for the Duberstein Group. Thomas will be the firm’s first new hire in almost a year — and the first woman ever to enter its lobbying ranks.

The six-member shop added Eric Ueland, former chief of staff to then-Senate Majority Leader Bill Frist (R-Tenn.), and Brian Griffin, a former Honeywell Inc. lobbyist, last April.

Thomas isn’t jumping far. Duberstein has long been an outside consultant to Goldman and she is expected to continue as a for-hire lobbyist for the bank.

Both Goldman and Duberstein enjoy reputations as white-shoe firms.

Founded by Ken Duberstein, who spent the last six months of Ronald Reagan’s presidency as his chief of staff, the Duberstein firm has risen to the top echelon of lobby shops in Washington.

Unlike most lobby shops, Duberstein is able to charge a flat rate for most of its two dozen or so clients of $100,000 a quarter, according to Senate lobbying disclosure reports. Also unlike most lobby shops, it does not have a Web site.

While Goldman has kept a lower profile inside the Beltway than other financial-services firms, the bank has nonetheless worked to increase its presence in recent years.

“They are one of the most sophisticated lobbies in town because they apply their master-of-the-universe tactics they use on Wall Street in Washington,” said an outside lobbyist who formerly worked for Goldman. He said the firm prefers to focus on discreet issues that can be successfully lobbied, eschewing large, generic coalitions.

“They are an island unto themselves,” said another lobbyist who used to do Democratic consulting work for the former investment bank.

Thomas’ departure is the latest personnel blow in Washington to Goldman. Last year, the bank lost Jud Sommer, its longtime head of the Washington office, and Mark Patterson, its co-head of U.S. government relations.

Sommer exited to become UnitedHealth Group’s top lobbyist.

Patterson, who was a registered lobbyist until April 11, has been tapped to serve as chief of staff to Treasury Secretary Timothy Geithner.

Patterson, who joined Goldman in 2005 after serving as policy director for then- Senate Majority Leader Tom Daschle (D-S.D.), has drawn criticism for not meeting the Obama administration requirement that lobbyists who join the administration not work in areas on which they have lobbied in the past two years.

Goldman Sachs spokesman Michael DuVally declined to discuss personnel matters.

Goldman’s D.C.-based global head of government affairs is Faryar Shirzad, who was White House deputy assistant for international economic affairs and the deputy national security adviser for international economic affairs in the Bush administration.

Shirzad and Ann Costello, who runs the day-to-day Washington operation as head of U.S. government affairs, have worked to beef up Goldman’s in-house operation since Patterson’s departure.

The firm hired Democrat Kenneth Connolly and Todd Malan in April. Connolly joined Goldman from ML Strategies, which also lobbies on behalf of the investment firm.

Malan was the longtime president of the Organization for International Investment, the lobby for foreign-based companies with U.S. subsidiaries.

Goldman, which spent more than $5 million on federal lobbying in 2008, also uses several outside consultants, including the Baptista Group, the Rich Feuer Group, Duberstein Group, John T. O’Rourke and ML Strategies, according to the firm’s year-end lobby disclosure filings.

Getting a senior in-house Democrat to replace Thomas is likely to be key for Goldman, which faces a far more hostile regulatory environment than in the past.

“They, like every other former investment bank, are looking at significant constraints on what they are going to be allowed to do and what they can afford to do,” said Kenneth Kies, a tax lobbyist at Federal Policy Group.