Sen. Pete Domenici of New Mexico, an influential Republican voice on budget issues for a generation, intends to retire at the end of his term next year for health reasons, party officials said Wednesday.
The 75-year-old, six-term lawmaker plans a formal announcement Thursday in his home state.
Domenici began informing associates late Wednesday he has frontotemporal lobar degeneration, a progressive disease that in some forms can cause dysfunction in the parts of the brain important for organization, decision-making and control of mood and behavior.
One Republican familiar with the senator's plans said Domenici is expected to announce that while he is confident of his ability to serve the remaining 14 months of his current term, he does not want to risk impairment over an additional six years in office.
Domenici would be the fifth Republican senator to decline to seek a new term, giving Democrats an opportunity to expand their narrow majority in the 2008 elections. GOP Sens. John Warner of Virginia, Chuck Hagel of Nebraska, Wayne Allard of Colorado and Larry Craig of Idaho have previously announced plans not to run again.
New Mexico, Virginia and Colorado are seen as highly competitive states, and the Nebraska race could prove tight as well. President Bush carried New Mexico by a single percentage point over Sen. John Kerry in 2004.
A spokesman for the National Republican Senatorial Committee did not immediately respond to a request for comment.
Colleagues had expected Domenici to seek a seventh term despite criticism over his possible role in the firing U.S. Attorney David Iglesias. Domenici has acknowledged phoning Iglesias at a time when some Republicans wanted the prosecutor to hasten an investigation of Democrats before the 2006 elections.
A Domenici adviser said health concerns are the main reason for the decision to retire.
Budget issues have dominated Domenici's long Senate career. He was the longtime chairman of the Budget Committee dating to President Reagan's first term. He is currently the top Republican on the Energy Committee.
He was a principal architect of a 1997 balanced budget bill negotiated with then-President Clinton, and has been a major player on national energy legislation. He has supported nuclear power and opening the Arctic National Wildlife Refuge to drilling.
Domenici earned a reputation as an advocate for his state from his perch on the powerful Appropriations Committee, steering money to Energy Department nuclear facilities such as the Los Alamos National Laboratory.
He now is one of the Senate's "Old Bulls," combining affectionate respect and fear to become one of the chamber's more powerful GOP members.
Domenici's health became an issue after he suffered nerve damage in his right arm while playing touch football with his grandchildren on Thanksgiving Day 1999. He underwent surgery in June 2000 to relieve pressure on nerves in his neck.
But the pain persisted and in 2003 he was diagnosed with arthritis in his lower back. The senator began using a low-speed scooter between his office and the Capitol. But the scooter disappeared two years later after a new workout regimen and treatment by arthritis specialists.
Domenici came under investigation by the Senate Ethics Committee this year after a watchdog group accused him of trying to pressure Iglesias to rush a corruption probe against Democrats to sway the 2006 elections. Iglesias says he believes he was dismissed from his job for resisting Domenici and Rep. Heather Wilson, R-N.M., who both say they did not pressure him.
In March, Domenici called the controversy "hell" like he had never experienced in his career.
Domenici was first elected to the Senate in the GOP landslide of 1972. His only serious challenge since came in 1978.
His retirement is expected to spur a scramble among the state's top politicians who have long hoped to succeed him. Among them are Republicans Wilson and Rep. Steve Pearce and Democratic Rep. Tom Udall. Other possible Democratic contenders include Albuquerque Mayor Martin J. Chavez and state Lt. Gov. Diane Denish.
Domenici "is an iconic figure here in New Mexico," said Paul Kennedy, a former state Supreme Court justice and a longtime Republican. "He's probably the most popular politician in its history. He had a great run, and he'll be sorely missed from the delegation."
Domenici is slated to make the announcement at St. Mary's School in Albuquerque at 4 p.m. local time. He attended the school as a youth and his sister Marianella is the principal.