Other lobbyists serve on one of Mr. Romney’s policy advisory teams, have hosted fund-raisers for his campaign or have joined the many influential Republicans whose endorsements Mr. Romney’s campaign has hailed. Among them are David Wilkins, a former United States ambassador to Canada who lobbies for the Canadian oil industry, and Stephen Rademaker, a former State Department official who lobbies for the defense contractor General Dynamics.

Many of the lobbyists advising Mr. Romney, like Mr. Black and Mr. Berman, are veterans of other Republican presidential campaigns, including Senator John McCain’s four years ago.

“These are the people who have made a career at the intersection of policy and presidential campaigns,” said David A. Donnelly, executive director of Public Campaign Action Fund, which advocates for public financing of elections and tracks campaign contributions. “To the extent that Mitt Romney depends on these people, and he gets elected, it’s four more years of business as usual in Washington.”

A spokeswoman for Mr. Romney did not respond to requests for comment. In an era when K Street firms serve as holding pens for political operatives and landing pads for retired lawmakers of both parties, the profusion of lobbyists around Mr. Romney’s campaign in part reflects the growing embrace of his candidacy by the Republican establishment, including most of the party’s elite donors and dozens of members of Congress.

His supporters disputed the notion that Mr. Romney’s case against the Washington establishment was undercut by his deep ties to it.