BOISE, Idaho, Sept. 1 — Concluding that his political career is over, Senator Larry E. Craig of Idaho announced his resignation here today.
The announcement marked the end of a stunning week in which Mr. Craig fell from senior senator to Republican Party outcast over reports that he solicited sex in an airport bathroom.
“What is best for Idaho has always been the focus of my efforts and it is no different today,” Mr. Craig said. “To Idahoans I represent, to my staff, my Senate colleagues but most importantly to my wife and my family, I apologize for what I have caused. I am deeply sorry.
“I have little control over what people choose to believe but clearly my name is important to me. And my family is so very important also. Having said that, to pursue my legal options as I continue to serve Idaho would be an unwanted and unfair distraction of my job and for my Senate colleagues.”
Citing the war in Iraq, he added: The people of Idaho deserve a senator who can devote a hundred percent of his time and effort to the critical issues of our state and our nation.” The senator faced overwhelming pressure from national Republican leaders determined to prevent the matter from becoming a burden in the autumn Congressional session and next year’s election. Mr. Craig, who served a decade in the House and 17 years in the Senate as a strong advocate for Republican positions on gun control, the use of Western lands as natural resources, abortion and gun control, said he would step aside Sept. 30, making way for a successor to be appointed by Gov. C. L. Otter, a Republican who stood behind Mr. Craig as he made the announcement today.
Many prominent Republicans in Idaho said they were in disbelief at the turn of events over the past week. They expressed sympathy and gratitude for a powerful senator who had supported their campaigns and brought millions of dollars in federal money to Idaho. Still, for all the upheaval, the prospect of political change also brought focus to state Republicans.
Before Monday, when news of his guilty plea to a misdemeanor charge of disorderly conduct in a men’s room at the Minneapolis-St. Paul International Airport became public, Mr. Craig had been a senator on August recess. Now Governor Otter, known as Butch, will decide who to send to Washington to represent the state when Mr. Craig’s resignation becomes effective. The new senator will complete Mr. Craig’s current term, which ends in January 2009.
Although Mr. Otter, a Republican with a tendency to defy expectations, refused to discuss who he might appoint, by early today he was widely believed to be leaning toward selecting the lieutenant governor, James E. Risch.
Governor Otter said today: “I have made no decision on that. Any report to the contrary is dead wrong.”
When asked about the time frame for a decision, he said, “at my pace.”
Mr. Risch, a Republican first elected lieutenant governor in 2002, served as interim governor for seven months last year after President Bush named Gov. Dirk A. Kempthorne as Interior Secretary. Last year, rather than run for a full term, he deferred to Mr. Otter, a congressman who had announced his intentions to run for governor if Mr. Kempthorne stepped aside.
Mr. Risch, who spent more than two decades in the State Senate, including six years as Senate president pro tem, had expressed interest in running for the seat in 2008 if Mr. Craig chose to retire. Even before the events of the past week, Senator Craig, 62 and serving his third term, had suggested he might not seek a fourth.
Mr. Risch and Mr. Otter are not close, and some Republicans suggested that Mr. Otter would not be sad to see him move to Washington. Yet Republicans also said Mr. Risch was a safe choice who had earned good will in the state and would not have to work hard to win a full term in 2008.
“Jim Risch is very electable, as he’s just proved,” said Norm Semanko, a Republican activist from Eagle, Idaho, referring to Mr. Risch’s wide margin of victory last fall for lieutenant governor. “He will be very warmly received.”
A Democrat, Larry LaRocco, is also running for the seat in 2008, but political analysts say they expect a Republican, whether it is the one Mr. Otter appoints or someone else, to win a full term next fall in this conservative state.
If he had run, Mr. Craig was widely expected to win another term, but that was before this week.
United States Senator Larry Craig (R-ID) resigned Saturday, five days after Craig's arrest for lewd conduct in a public restroom was first reported.

In a news conference in Boise, Idaho, Senator Craig apologized for his actions, but insisted that he had not engaged in gay sex, and that the June 11 incident at Minneapolis-Saint Paul International Airport was a misunderstanding.

"To Idahoans I represent, to my staff, my Senate colleagues but most importantly to my wife and my family, I apologize for what I have caused. I am deeply sorry," Craig said Saturday.  "I have little control over what people choose to believe but clearly my name is important to me. And my family is so very important also. Having said that, to pursue my legal options as I continue to serve Idaho would be an unwanted and unfair distraction of my job and for my Senate colleagues."

It was revealed on Monday that Craig pled guilty to disorderly conduct after allegedly soliciting sex in the men's room of a Minnesota airport.  Craig, who voted against gay marriage and gay rights bills numerous times over the course of his 17-year career in the Senate, has denied rumors about his sexuality since the 1980s, when he served in the U.S. House of Representatives.

Craig's resignation is effective September 30.  His replacement, who will serve until January 2009, will be named by Idaho Governor C.L. "Butch" Otter; it is believed that Idaho Lieutenant Governor Jim Risch will be named to the post.