WASHINGTON  - On Christmas Eve 1994, Fred D. Thompson Jr. was out of a job. A 34-year-old self-described late bloomer, Mr. Thompson had graduated from law school just two years before and practiced law only for his father, Fred D. Thompson Sr., who was about to be sworn in as a senator from Tennessee.

"I was out on the street, knocking on doors," recalled the younger Mr. Thompson, who is known as Tony.

But attending Brentwood Methodist Church in Nashville that night, Tony Thompson ran into the departing incumbent senator, Harlan Mathews, a Democrat. Mr. Mathews invited Tony to join him in a Nashville lobbying business, a job that would let him capitalize on his father's new position.

"I don't just believe in the tooth fairy," Mr. Mathews said. "A lot of people were seeking access - not necessarily unfair access, but seeking access - so Tony was employed in a number of areas where his father had made a reputation or his father's advice or whatever was going to be valuable one of these days."

Now the elder Mr. Thompson, who also worked as a lobbyist before and after his eight years in the Senate, is aiming for an even higher post, preparing a run for the Republican presidential nomination. In the folksy drawl that built him a lucrative sideline as a screen actor, Mr. Thompson is presenting himself as a reform-minded outsider taking on Washington, just as he did when he campaigned for the Senate as "Ol' Fred" the "real live country lawyer," and cruised Tennessee in a rented red pickup truck.

But the lobbying work that Tony Thompson and another son, Daniel, did after their father won his Senate seat suggests how far the family has traveled from Fred Thompson's early career. Not only has he parlayed his own political background into a lobbying business - a fact his opponents have seized on to challenge his outsider image - but his sons have also made lobbying a family affair.

Mr. Thompson and his advisers declined to comment. Although clients valued Tony Thompson's service because of the perception that he had access to his father, Mr. Mathews said, Senator Thompson was sensitive to the potential appearance of favoritism to his sons' clients and sought to keep a distance. Rather than relying on his father, Tony Thompson relied mainly on political contacts in Tennessee he had made campaigning for his father, Mr. Mathews said.

Tony Thompson said he lobbied mainly in Nashville and registered for only one Washington client, Lockheed Martin. He said he never lobbied the Senate or discussed clients with his father.

Daniel Thompson was registered as a lobbyist only at the state level, where he worked as executive director of a statewide business group, the Tennessee Business Roundtable. He was later also a paid consultant to his father's political action committee. Daniel, too, declined to comment.

Paul C. Light, a professor of government at New York University who worked closely with Senator Thompson on campaign finance and ethics proposals, said that lobbying by a family member was "an ugly practice no matter who the senator is, because it creates the appearance that his family is exploiting his stature and position."

Mr. Thompson was hardly the only lawmaker with relatives in similar positions. As money pouring into lobbying firms has soared in recent years, many lawmakers have watched family members get into the business. But ethics experts say the case is all the more striking when the relatives, like Tony and Daniel Thompson, have scant qualifications other than their family ties. And the elder Mr. Thompson was one of the Senate's most outspoken advocates of tighter ethics and campaign finance rules.

Some groups whose interests and causes the elder Mr. Thompson supported in the Senate also hired his sons. In 1998, for example, Lockheed Martin hired Tony Thompson and his partner, Mr. Mathews, to lobby the federal government to maintain contracts to manage federal nuclear facilities in Oak Ridge, Tenn.

Lockheed had been a major source of money for Mr. Thompson's Senate campaigns; around the same time he had hired a former Lockheed lobbyist, Powell A. Moore, as his chief of staff. In November that year, Mr. Thompson and Tennessee's other senator, Bill Frist, invited Bill Richardson, then the energy secretary, for a tour of the facility to make the case for retaining Lockheed.

The next month, Mr. Richardson deferred a decision about the fate of the contracts for 15 months. "Secretary Richardson is to be commended for making a thoughtful decision," Mr. Thompson said at the time.

Lockheed lost the Oak Ridge contracts in 2000, two years before Mr. Thompson left the Senate. The loss of the contracts, Tony Thompson argued, showed that there was "obviously no connection" to his father.

There were some causes that the senator supported before his son lobbied for them. As an actor, for example, Senator Thompson was a natural champion for the Motion Picture Association of America on subjects like copyright protection and obscenity regulation. As a former trial lawyer, he was sometimes one of the few Republicans to oppose limits on personal injury suits and lawyers fees. And as a former lobbyist for certain cable television concerns, it may have been natural that Mr. Thompson supported the cable television industry's goals in a regulatory overhaul of the telecommunications industry.

The same groups also hired Tony Thompson to lobby in the Tennessee Capitol. One of Tony Thompson's first state-level lobbying clients was the Motion Picture Association of America. Other early clients included Time Warner cable and its allied Interactive Services Association. In 2006, after the elder Mr. Thompson had left the Senate, the Tennessee Trial Lawyers Association hired Tony Thompson.

Connections to a senator can also be a significant calling card for a lobbyist in the halls of a state capitol. Senators are leaders of their state political parties with broad power over federal appointments, spending and other forms of patronage.

Tony Thompson said he never traded on his father's name. "People at the State Legislature from time to time would ask me how my dad is doing," he said. "You know, they're politicians."

Mr. Thompson, who had his first son by the time he finished high school and his second by the time he finished Vanderbilt Law School, started out working with an in-law in his hometown, Lawrenceburg. His big break came when Senator Howard H. Baker Jr., whose 1972 re-election campaign Mr. Thompson had worked for, tapped him as the Republican counsel to the Senate Watergate committee, and he quickly parlayed the celebrity he gained through the televised hearings into a small Washington lobbying business.

His first and biggest lobbying client was a division of Westinghouse, which hired him to seek federal money for an experimental nuclear reactor on the Clinch River in Tennessee. The project cost about $1.7 billion in taxpayers' money before it was killed in 1983, surviving primarily because of the support of Mr. Thompson's mentor, Mr. Baker.

Other clients included a Tennessee savings-and-loan group advocating some of the looser regulations that contributed to the savings and loan crisis; Jean-Bertrand Aristide, the leftist Haitian leader; Perrier; Toyota; a Teamsters pension fund; and a Baltimore-based group seeking federal business grants for urban neighborhoods. After leaving the Senate, Mr. Thompson, busy with his acting career, lobbied for just one client: Equitas, an insurance company concerned about asbestos liabilities.

Before his father's election, Tony Thompson had spent most of his 20s as a landscaper before finally earning a law degree from Memphis State University.

But he soon had a portfolio of clients including Coors Brewing, the Gallo wine company, a wine industry group, several waste services companies and a few health care companies, as well as the City of Knoxville, according to state records. Several continued to employ Mr. Thompson even after his father left the Senate.

Daniel Thompson had worked as a Xerox salesman before his father's election. Afterward, Daniel landed an economic development job for the state, and three years later became executive director of the Tennessee Business Roundtable. His duties included recruiting new members and lobbying at the Statehouse for increasing education and business development spending and lowering taxes.

In 2002, Daniel quit to work full time as finance director of his father's re-election campaign. When Senator Thompson decided not to seek re-election, Daniel, too, was out of a job. So his father stepped in to help out. Giving a speech to a charitable group associated with a Kentucky military base, Senator Thompson suggested to the group's fund-raising consultant, Douglas M. Lawson, that he consider hiring his son, Mr. Lawson recalled. Daniel now runs an office of Mr. Lawson's charitable fund-raising firm in Nashville, his father's home base.

The elder Mr. Thompson helped Daniel through his political action committee as well. In the last two elections, the committee paid Daniel Thompson more than $170,000 in consulting fees, compared with less than $70,000 it paid toward supporting Republican political campaigns.

E. Thomas Wood contributed reporting.

Copyright 2007 The New York Times Company