As a coalition led by Apple Inc., Google Inc., and Cisco Systems Inc. presses for a tax holiday on more than $1 trillion in offshore profits, it is turning to a well-positioned lobbyist: Jeffrey Forbes, once chief of staff to Max Baucus, chairman of the tax-writing Senate Finance Committee.

Data compiled by Bloomberg News show that Forbes is part of an army of more than 160 lobbyists, including at least 60 who once worked for a sitting member of the House or Senate, pushing for the repatriation holiday. Their job is to persuade Congress to establish a tax break estimated to cost the U.S. government $78.7 billion over the next decade.

Independent studies have found that the last time this tax break was tried, in 2004, the bargain rate for bringing home offshore profits did little to spur hiring or domestic investment. Most of the money was used to buy back stock.