Prominent Washington lobbyists also said that Mr. Trump would arrive in the capital with a much smaller contingent of veteran policy advisers than Hillary Clinton would have brought — and they see that relative inexperience as an opening. So they are prepared to draft legislation and regulations to quietly pass to allies on Capitol Hill and in the White House.

It is an opportunity that comes after a period of decline in lobbying revenues for many major firms. Total lobbying spending in Washington, after climbing consistently for nearly two decades began to dip in 2011, as congressional action slowed with divided government.

“Trump’s management style and policy approach to the campaign implies he is going to set big broad ‘beautiful’ direction and the elected lawmakers will take significant cuts at trying to flesh it out and reflect his will,” said Bruce P. Mehlman, the founder of Mehlman Castagnetti Rosen & Thomas, which has more than 70 clients ranging from Adobe, the software company, to Walmart.

Lobbyists will also be leveraging their relationships. Mr. Lott, for example, noted his longstanding friendship with Senator Jeff Sessions, Republican of Alabama, whose name has been mentioned as a possible secretary of defense, as well as his former aides like Rick Dearborn, a senior policy adviser to Mr. Trump, and David Hoppe, the chief of staff to Speaker Paul D. Ryan.

“There are going to be a lot of companies and people looking for guidance in how to deal with the legislative and executive branch,” Mr. Lott said. “I am looking forward to it.”

Republicans have pledged, if necessary, to repeal much of the Affordable Care Act or to pass changes in tax code using a process known as reconciliation that requires only a simple majority and not the 60 votes typically required for contentious matters, making the pitch for lobbyists somewhat easier.