Election Day defeats, retirements and departures for jobs in the Obama administration will leave Democrats and Republicans without key legislative dealmakers in the 111th Congress.

The defeat of Sen. Ted Stevens (Alaska), currently the longest-serving GOP Senator, will have a significant effect on the appropriations process and could influence energy and environmental policy as well.

Stevens has led or served in leadership slots on the Appropriations Committee for the past quarter century, where has been an unabashed backer of earmarking. He has directed billions of dollars to his home state of Alaska, often securing support by doling out earmarks to other Members.

Steve Ellis, vice president of Taxpayers for Common Sense, said Stevens presided over a massive increase of earmarks during his tenure as head of the Appropriations Committee, which he chaired from 1997 to 2005, except for 18 months when the Democrats controlled the Senate.

“It’s certainly one of his legacies,” Ellis said.

In recent years, Stevens led the Commerce, Science and Transportation Committee, where one of his major accomplishments was the 2005 legislation to hasten the switch to digital television.

The next year, however, Stevens failed to advance a sweeping telecommunications bill. The debate over that legislation led to his widely mocked description of the Internet as “a series of tubes.”

Stevens, whose first wife died in a plane crash in 1978, is also considered a strong advocate for airline safety, as well as for oil and gas interests that are an economic mainstay of Alaska. He has been a fierce proponent of drilling in the Arctic National Wildlife Refuge, calling the Senate’s 2005 rejection of an ANWR bill that he authored “the saddest day of my life.”

At least two Democratic Senators are leaving because they have been offered plum jobs by the Obama administration. No Democratic incumbents lost their Senate seats in this fall’s election.

Vice President-elect Joseph Biden (D-Del.) will resign after more than three decades in the Senate. Biden has been a leading voice on foreign policy issues as chairman or ranking member of the Foreign Relations Committee since 1997, and his close ties with foreign leaders are a key reason Obama selected him.

Biden is also a former chairman of the Judiciary Committee, where he oversaw several Supreme Court nominations and championed women’s rights and crime legislation. He’s expected to use that experience to help shepherd Obama court nominees through the Senate.

Sen. Hillary Rodham Clinton (D-N.Y.) is also expected to give up her seat to become secretary of State. While lacking in Senate seniority, Clinton has been a key voice on health care issues and earned her foreign policy stripes on the Armed Services Committee.

The retirement of longtime GOP Sens. John Warner (Va.) and Pete Domenici (N.M.) will leave the chamber without two of its top moderates who have shown a willingness to work with Democrats.

Domenici’s greatest legislative accomplishments came as chairman or ranking member of the Budget Committee for more than two decades, where he was the leading GOP budget hawk and sparred with House Republicans over tax cuts in the 1990s.

Since leaving the helm of that panel, Domenici has focused most of his effort over the past decade on promoting nuclear power, and the industry earlier this year credited his support for spawning a nuclear revival.

He holds top GOP slots on the Energy and Natural Resources panel and the Appropriations Committee.

Warner, a former Navy secretary under President Richard Nixon, served as chairman of the Armed Services Committee for most of the past decade. Initially a strong supporter of invading Iraq, Warner would eventually become a critic of the Bush administration’s handling of the conflict and was instrumental in forcing the Pentagon to adopt benchmarks for measuring success.

Warner also worked with Sen. Joe Lieberman (ID-Conn.) to pass the Lieberman-Warner Climate Security Act that sought to control global warming through the establishment of a federal cap-and-trade scheme. The measure ultimately stalled, but it was widely seem as a precursor to future climate change legislation.

Other key GOP moderates also failed to win re-election.

Sen. Gordon Smith (R-Ore.), who lost his bid for a third term, has worked across party lines on health care and energy legislation. He joined with Democrats in a failed bid to expand the State Children’s Health Insurance Program and has sponsored legislation with Sen. Edward Kennedy (D-Mass.) to expand federal hate-crime protections to gays.

Sen. John Sununu (N.H.), the chamber’s youngest GOP Member, lost his race for a second term. He often joined with Democrats on environmental issues and was among a handful of Republican Senators to vote in support of advancing the Lieberman-Warner Climate Security Act. Sununu also reached across party lines to work with Sen. Tim Johnson (D-S.D.) to push a regulatory overhaul of the insurance industry.

In the House, Rep. Christopher Shays (Conn.), the author of landmark campaign finance reform legislation in 2002, was defeated in bid for a 12th term. Shays was among the most moderate GOP Members, particularly on social issues, and was a frequent critic of the Bush administration. He was the lone Republican representing a New England state.

Also defeated was a top GOP appropriator, Rep. Joe Knollenberg (Mich.), ranking member of the Subcommittee on Transportation, Housing and Urban Development, and Related Agencies, a key slot given the automobile industry’s importance for his home state. He served as chairman for two years when the GOP controlled the House. Knollenberg opposed fuel-economy standards and free-trade agreements, and he has successfully zeroed out funding for the 1997 Kyoto treaty.

Several senior Republicans were defeated or opted to retire rather than seek re-election in the 111th Congress.

Rep. Jim McCrery (La.), the ranking member on the Ways and Means Committee, chose not to seek re-election after leapfrogging several Members in 2006 to take the panel’s minority gavel. McCrery has had a solid working relationship with Ways and Means Chairman Charlie Rangel (D-N.Y.) that helped them pass a package of small-business tax cuts. He also was a leading critic of the Democratic argument that the Internal Revenue Service is not doing enough to collect unpaid taxes.

Other key GOP retirees include: Rep. Duncan Hunter (Calif.), a former chairman of the Armed Services Committee and a staunch advocate of increased defense spending; Rep. Tom Reynolds (N.Y.), a Ways and Means member who led several efforts to delay the alternative minimum tax; Rep. Ray LaHood (Ill.), a centrist respected for his institutional knowledge; and Rep. Tom Tancredo (Colo.), an outspoken critic of illegal immigration.

No senior Democrats lost their bids for re-election.

Among the most significant Democrats leaving is Rep. Rahm Emanuel (Ill.), the tenacious House Democratic Caucus Chairman, who will become Obama’s White House chief of staff. Despite his hard-charging reputation, Emanuel has been a deal-maker in House and willing to work with Republicans to pass legislation.

Geof Koss, Vicki Needham and Stephen Langel contributed to this report.