Lobbying filings show Hart has also has represented a wide variety of industry advocacy groups, from the American Bankers Association to Wine and Spirit Wholesalers of America. He is also a top GOP fundraiser, according to a 2011 article in The Hill.

Much of Hart’s lobbying work has focused on tax and benefits issues. Filings also show that Hart lobbies on a wide variety of topics—including transportation appropriations, financial regulations and homeland security.

Related: Trump, GOP could torpedo DOL fiduciary rule, Dodd-Frank

Before joining Williams & Jensen, Hart worked in the Pension Welfare Benefits Program—now called the Employee Benefits Security Administration. The agency is responsible for enforcing the Employee Retirement Income Security Act of 1974, the act that creates minimum standards for private health and pension plans.

He also worked for the Pension Benefits Guaranty Corporation, a government agency in charge of protecting retirement income, and has served on an ERISA task force at White House Office of Management and Budget.

Tax, benefits and retirement issues are slated for new scrutiny under Trump’s Labor Department.

Under its current head, Thomas Perez, the department finalized its fiduciary rule in April, which is aimed at minimizing conflicts of interest in the retirement-planning industry.

Some observers expect the Trump administration to dismantle the rule, although others disagree that he would make that a priority.

Hart during the Reagan administration served as the Justice Department’s special assistant in charge of processing federal judicial nominations.

Hart, with his breadth of clients and connections to major corporations, is a rainmaker for Williams & Jensen.

A 2014 study from the nonprofit Sunlight Foundation found he had raked in more than $1 million in annual revenue for his firm, which has lobbyists connected to both major political parties, in 13 of the preceding 15 years.

Trump has not revealed many specifics on the labor and employment front. He has released a paid maternity-leave plan and spoken about the minimum wage. The expectation from labor and employment lawyers was that Trump’s policies and personnel appointments in the labor field would lean conservative.

“[Trump appointees] would have very different views of labor and employment issues than the people who have occupied those positions in the last several years,” said Michael Lotito, a partner at Littler Mendelson in San Francisco who represents employers in labor cases.

Donald Schroeder, a partner at Foley & Lardner’s Boston office who represents employers, speculated that under Trump there would be a return to the George W. Bush years in the form of pro-business decisions from the Labor Department, the National Labor Relations Board and the Equal Employment Opportunity Commission.