President-elect Donald Trump stops to talk to the media in the lobby of Trump Tower December 6, 2016 in New York. (Timothy A. Clary/AFP/Getty Images)

The Angel Capital Association worked over the Thanksgiving holiday to put together its wish list for President-elect Donald Trump.

Its four-page letter was full of regulatory tweaks and legislative items that the niche group of wealthy investors hoped the new administration could deliver. The investor group also urged the nomination of two new Securities and Exchange Commission members, and it had a perfect candidate to suggest: Joe Wallin, a member of its public policy ­council.

“We anticipate that the people on the transition team will be inundated with ideas and proposals as well as names,” said Linda Smith, vice president of the Angel Capital Association, whose members help finance fledgling companies. “We wanted to get on the radar screen.”

The election of Trump has set off a tsunami of lobbying activity by companies eager to cash in on the inauguration of the nation’s businessman president. For executives who had been bracing for the tough-minded plans of Democratic nominee Hillary Clinton, Trump holds out the promise of stripping away regulations, appointing business-friendly officials and overhauling the tax code in ways that could benefit their enterprises.

“I would say that for a majority of the sectors out there, this was a surprise and not the bet they made” on the election outcome, said Bob Wood, president of government affairs at the lobbying firm Barbour, Griffith and Rogers. “Almost across the board, there was a sigh of relief.”

That relief has quickly turned to action. Trade groups are revising their priority lists. Republican lobbyists are suddenly in greater demand. And everyone is trying to figure out who will matter most in the emerging Trump administration.

One thing seems certain: With Republicans in charge of the House, the Senate and the executive branch, much of the action will probably move back to Congress after eight years of legislative gridlock. And that holds out potential benefits and dangers as interest groups jockey to insert possibly lucrative items into comprehensive bills on health care, taxes, financial changes and other budget items.

“We’re trying to figure out how to manage expectations,” said John Feehery, director of government affairs at Quinn Gillespie & Associates, a leading lobbying firm. “But understand that we are not going to have an administration that has a disgust and dislike for the business community.”

The supplicants are many. The Alliance of Automobile Manufacturers, which includes a dozen major carmakers, sent a memo to the Trump transition team two days after the election, pressing for a rollback in fuel-efficiency standards that President Obama set at the beginning of his term.

The letter said its members wanted the Trump administration to “harmonize and adjust” the fuel-efficiency standards that it said “pose a substantial challenge to the auto sector due to the steeper compliance requirements for model years 2017-2025.” The Obama administration has just reaffirmed its mileage targets, saying the industry is ahead of schedule and possesses the technology to go further.

The health-care industry — encompassing doctors, hospitals, health services and pharmaceuticals, which collectively spend about half a billion dollars a year on lobbying — is eager to capi­tal­ize on Trump’s early vow to abolish Obama’s Affordable Care Act and his later pledge to keep parts of it.

“The device tax, the health insurance tax, the Cadillac tax — certainly all those are on the chopping blocks,” said Wood, the lobbyist. Those items — the tax on medical devices, penalties for not signing up for insurance and a surcharge on especially generous employer plans — were central to Obama’s effort to raise revenue to deliver affordable coverage to millions of uninsured Americans.

The health-care industry, like many others, is not a monolith, though.

The American Hospital Association and the Federation of American Hospitals have a separate overriding issue: stopping the deep cuts in Medicare re­imbursements that were part of the Obama health-care changes and that will begin to take effect next year. Tens of billions of dollars are at stake for doctors and hospitals. Their slogan is to “repeal, restore and replace.” Restore means restoring Medicare and Medicaid payments.

Suddenly, the hospitals have reason to hope. The dozens of House bills passed in recent years to end Obamacare kept the Medicare cuts in place so the savings could be used to balance other spending or tax-cut plans. But there was an exception. The one GOP House member who proposed a bill that would have canceled the Medicare cuts was Rep. Tom Price (R-Ga.) — Trump’s choice for secretary of health and human services and the person who will play a key role in how the Trump administration unravels health-care restructuring.

The oil industry also stands to reap benefits, and not just in the most obvious ways. For example, the selection of a new Securities and Exchange Commission chairman more friendly to banks could help oil and gas firms, which have been pressured to include in their SEC disclosures calculations about climate risk and more information about their political contributions.

Trump’s promise of a thaw in relations with Russia could also help oil and gas companies if he lifts economic sanctions imposed after Russia annexed Crimea. Those sanctions targeted the banking and energy sectors, and forced ExxonMobil to halt an Arctic exploration project — although it still possesses widespread drilling rights in Russia.

Boeing also would benefit from a lifting of sanctions on Russia because those who may buy its aircraft are blocked from getting financing under the ­sanctions.

For years, the for-profit education industry has been buffeted by Education Department requirements after scandals about false advertising, poor job placement records and high levels of defaults on federal student loans. The industry expects a softer touch from the Trump administration, because of Trump’s views on regulation and because of his ownership of Trump University, which recently paid $25 million to settle charges of wrongdoing.

Shares of leading for-profit education companies have jumped. Apollo Education is up 8 percent, Strayer Education and DeVry Education Group have each climbed 28 percent, and Grand Canyon Education has risen 30 percent over the past month.

The telecommunications industry also is keeping a close eye on developments at the Federal Communications Commission. The Trump transition has announced three people on its FCC landing team, all of whom come from the American Enterprise Institute and all of whom are foes of the agency’s net neutrality rules.

Those rules give free, speedy access to the Internet. But big communications companies, which own the infrastructure for connecting to the Internet, want to give favorable access speeds and prices to their own companies or to special customers. Rolling back those rules would benefit companies such as Comcast, which has been seeking to acquire cable companies and greater control over Web access.

“Net neutrality in the U.S. is backfiring,” Mark Jamison, one of the landing team members, wrote in a blog post in June 2015. He mentioned “a growing miscellany of ex ante regulations that frequently work against the entrepreneurs and consumers the rules are intended to help.”

Yet Trump could also pose a danger to companies.

Although Boeing could benefit from a lifting of Russia sanctions, the airline manufacturer could suffer a loss of sales to Iran if Trump tears up the accord limiting Iran’s nuclear program. And Trump has vowed to cancel Boeing’s contract to design a new Air Force One.

The president-elect’s threats about tariffs have sparked talk about a “border adjustment tax” that would impose a fee on all imported goods. It would raise $1 trillion over five years — and hurt a broad cross-section of corporate America, tripling its tax bills in some cases.

Another key player in the new Trump era is likely to be Congress.

“You have one-party control, but the activity is not going to be limited to the administration,” Wood said. “People shouldn’t forget about Congress. Congress is going to play a huge role in implementing a majority of these policies.”

And once lawmakers roll up their sleeves on a comprehensive health-care, tax or spending bill, anything could happen. As one lobbyist, who spoke on the condition of anonymity to protect his business and lobbying contacts, put it: “In budget reconciliation, I have a vehicle. You can hide a lot of things in the budget ­reconciliation.”