In a historic election that saw America’s first African-American president and expanded Democratic majorities in Congress, K Street was cheering for something else as well: a cornucopia of potential new business.

“We’re hearing a lot from banking and the securities industry and transportation. They’re going to be hot,” said Diane Blagman, a veteran lobbyist at Greenberg Traurig.

Excitement at the prospects of record fees next year, however, was tempered by fears — and anger — about the type of restrictions an Obama administration might place on its hiring of any of the city’s tens of thousands of lobbyists.

“Talking to people around town, there are a lot of Democratic lobbyists who would love to serve in an Obama administration, if they can get around these crazy proposed lobbying restrictions,” said Elizabeth Moeller, who heads the public policy group at Pillsbury Winthrop Shaw Pittman.

It’s unclear exactly how the new administration plans to handle lobbyists’ résumés — rumors range from an outright ban on the hiring of anyone who has been a registered lobbyist to permitting lobbyists to work for the administration provided they don’t handle issues for which they were previously paid to lobby on the Hill.

Many lobbyists appear to be expecting a solution that is less in line with both the Republican and Democratic campaigns’ anti-lobbyists rhetoric and more in keeping with the realities of running a complex government, if only because many lobbyists are technical experts whose skills may prove too useful to ignore.

More immediately, however, is the prospect of a real bounty of new clients.

“A lot of issues we’ve been working on, like climate change and renewable energy, have gone from simmering to about to hit boiling,” Moeller said.

Health care reform, as well, noted Karen Ignagni, who runs America’s Health Insurance Plans, is going to be big.

“We think the economic situation has exacerbated the need for Congress to prioritize this issue,” said Ignagni, whose group represents HMOs. “We don’t buy into the idea that a minimal plan is enough. I think there is a real opportunity to discuss comprehensive reform.”

K Street should also be energized by a real fear among many in corporate America that the new Democratic administration is going to be regulation-heavy.

“People are saying: ‘This is going to be horrible, Obama’s going to regulate everything. The horrible people are going to take over,’” said one lobbyist who did not wish to be identified.

There are other changes that also might come to the industry, including more sunlight on how lobbyists work, said former five-term Rep. Dan Mica (D-Fla.), who now runs the National Credit Union Association.

“The Obama camp has had study groups working all summer long on changes they would make on how advocacy would take place in this town,” Mica said.

“They’re talking about having complete and total transparency in advocacy. I say, that’s tremendous. That is a boon to the credit union system. We don’t have the money that some of our adversaries have. If it is fully transparent,” Mica said, “we’ll go toe to toe with anybody.”

T.R. Goldman contributed to this report.