But some of those lobbyists will carry a bit more weight — or at least a heftier client list — than others.

A new analysis of Senate disclosure records by The Center for Public Integrity found that 10 lobbying firms — all with deep ties to Capitol Hill — have amassed such large client lists that they represent nearly 100 of the business stakeholders in the legislative brawl. Here they are:

Alpine Group — 13 clients

It’s no surprise that Alpine Group tops the list, given its environment and energy pedigree. The shop was co-founded in 1996 by Richard White, former legislative coordinator for the late Sen. John Chafee (R-R.I.), who often bucked his party as an environmental champion, and by James Massie, a longtime energy lobbyist. Alpine Group’s stable of climate lobbyists includes former House Energy and Commerce Committee Democratic aide Courtney Johnson, former Senate Appropriations Republican staffer Les Spivey and former aides to three Democratic senators — Sen. Mary Landrieu of Louisiana, Sen. Blanche Lincoln of Arkansas and Sen. Sherrod Brown of Ohio — who could tip an eventual Senate vote. Alpine Group’s list of 13 climate clients includes Ford, BP America, BNSF Railway, 3M, Duke Energy and NRG Energy.

Ogilvy Government Relations — 13 clients

The firm formerly known as the Federalist Group was founded by Stewart Hall, a former legislative director for Sen. Richard Shelby (R-Ala.), who opposed similar legislation last year. Joining Hall in representing some of the biggest oil and chemical groups — the American Petroleum Institute and the American Chemistry Council, as well as power companies and agriculture groups — are Julie Dammann, onetime chief of staff to Sen. Kit Bond (R-Mo.), and Dean Aguillen, a former senior aide to House Speaker Nancy Pelosi (D-Calif.). Reliant Energy, Chevron, Monsanto and the National Milk Producers Federation count themselves among Ogilvy clients.

Patton Boggs LLP — 11 clients

Patton Boggs represented 10 local governments in the first quarter, in addition to chemical manufacturer INEOS. Nearing a half-century old, Patton Boggs has been the king of K Street since it eclipsed Cassidy & Associates as the highest-paid lobbying firm in 2003, according to the Center for Responsive Politics. Patton is home to a pair of municipally minded climate lobbyists: Tanya DeRivi, a former adviser to the Los Angeles Department of Water and Power, and Marek Gootman, a former adviser on community development policy and intergovernmental affairs at the U.S. Department of Health and Human Services.

Morgan Meguire, LLC — 11 clients

This specialized firm is led by Deborah Sliz, who started her career in the late 1970s as counsel to one of Capitol Hill’s most legendary environmental advocates, the late Rep. Morris Udall (D-Ariz.). Udall’s son Mark is now Colorado’s freshman Democratic senator. Sliz’s climate clients include some of the nation’s biggest public and consumer-owned water and power utility groups. Among them are Southern California’s Imperial Irrigation District, the Tennessee Valley Public Power Association and the Northwest Public Power Association. Another Morgan Meguire climate lobbyist, Karen Zanoff, came to the firm after serving as a staffer on the House Energy and Commerce Committee, as an adviser to former Rep. Karen McCarthy (D-Mo.).

McBee Strategic Consulting — 10 clients

The client list at McBee Strategic Consulting is diverse, and so are its lobbyists. McBee’s roster includes a bipartisan pair of former counsels to the Senate Commerce, Science, and Transportation Committee (Democrat Samuel Whitehorn and Republican Robert Chamberlin) and a bipartisan pair of former legislative aides to Washington state lawmakers. Steve McBee worked for Sen. Maria Cantwell when she served in the House. Ashley Slater was director of legislative affairs at the White House Council on Environmental Quality under President George W. Bush. Her colleague Glynda Becker also served in the Bush administration as associate political director. McBee’s clients include JPMorgan Chase, Boeing and Eastman Chemical. The Port of Seattle, the American Trucking Associations and alternative energy firm Akermin are among other clients.

Ryan, MacKinnon, Vasapoli and Berzok LLP — 9 clients

The first two name partners, Thomas M. Ryan and Jeff MacKinnon, both have close ties to the House Energy and Commerce Committee. Ryan was a Democratic aide and MacKinnon was legislative director to Rep. Joe Barton (R-Texas), who is the ranking minority member of the committee. The firm represents the giant association of investor-owned electric power companies, Edison Electric Institute, as well as Southern Co., Entergy, Sunoco and the Association of American Railroads.

Bracewell & Giuliani LLP — 9 clients

Some of the nation’s largest coal-intensive power companies, including Southern Co., Duke Energy and Energy Future Holdings, as well as coal-hauling rail company CSX, are on the climate client roster of Bracewell & Giuliani. The firm’s renowned name partner is former New York mayor and Republican presidential candidate Rudy Giuliani, who joined Bracewell in 2005. But the energy and climate lobbying team is led by attorney Scott Segal. He was joined in recent years by two of George W. Bush’s senior appointees at the Environmental Protection Agency, Jeffrey Holmstead and Edward Krenik.

Alcalde & Fay — 8 clients

The so-called super-greenhouse gases are the focus of Alcalde & Fay’s lobbying work. Not carbon dioxide, but an array of gases used in refrigerators and air conditioners and called hydrofluorocarbons, which are thousands of times more potent in trapping heat in the atmosphere. A possible phase-down of these gases is one of the issues lawmakers are grappling with. Alcalde & Fay’s two lead climate lobbyists, Kevin Fay and David Stirpe, worked on regulatory controversies before, including a long-fought battle over asbestos. Now they represent the HFC manufacturer and user group the Alliance for Responsible Atmospheric Policy. Other clients include Dow Agrosciences, American Pacific and the Air Conditioning, Heating and Refrigeration Institute.

Colling Swift & Hynes — 7 clients

With former Rep. Allan Swift (D-Wash.) leading its climate lobbying effort, this firm has been a magnet for companies from an industry that once was key in Swift’s home state: the paper business. Clients include Rock-Tenn Co., the Newark Group, White Pigeon Paper and Smurfit-Stone Container. In addition to Swift, the team includes Louis Hengen, once an aide to former Senate Majority Leader Trent Lott (R-Miss.) and Frances McPoland, who coordinated federal recycling and waste reduction programs in President Bill Clinton’s White House.

Hunton & Williams LLP — 7 clients

While McBee nabbed two former Senate committee lawyers, Hunton & Williams landed two former Republican counsels to the House Energy and Commerce Committee. Mark Menezes and Joseph C. Stanko are among the climate lobbyists working on behalf of electric power clients including First Energy, as well as the Gas Processors Association, manufacturer Koch Industries and railroad company CSX. Hunton & Williams represented utilities on the losing side in the Supreme Court’s ruling in Massachusetts v. EPA, in which the court determined that the agency could regulate greenhouse gases under the Clean Air Act. However, that issue is now very much in play for the firm’s climate lobbying clients on Capitol Hill, as the proposed Waxman-Markey legislation would take away EPA’s power — putting into place the cap-and-trade system to control greenhouse gases instead.

Marianne Lavelle and Matthew Lewis are staff writers at the Center for Public Integrity. Data editor David Donald and staff writer M.B. Pell contributed to this report.