Sen. Mike Crapo said Friday that he began drinking alcohol for the first time in his life last year as a way to deal with on-the-job stress in Congress.

Crapo said he was drinking once or twice a week, always alone in his apartment in Washington, D.C.

When he drove early on the morning of Dec. 23 after having “two to three” vodka tonics, Crapo said it was the first time he had driven after drinking. He said his family and staff were unaware that he had been imbibing.

“Everybody back here is stressed, and what I did was a very poor choice on how to deal with that stress,” Crapo said. “I am swearing off alcohol.”

Before a conference call with Idaho reporters, Crapo stood in an Alexandria, Va., courtroom Friday morning and pleaded guilty to drunken driving.

His voice cracking as he admitted “embarrassment and shame,” Crapo faced a judge and admitted committing the misdemeanor. He was fined $250, had his driving privileges taken away and received a suspended sentence of 180 days in jail. He also was ordered to attend alcohol awareness classes for 10 weeks.

“I sincerely regret the choice I made,” he said in a statement read before a bank of television cameras on the courthouse steps after the three-minute hearing. “I’m grateful, truly grateful, no one was injured.”

Alexandria police stopped Crapo shortly before 1 a.m. after he ran a red light. Police said his blood alcohol content at that time was 0.11 percent. A second test at the local jail found the level at 0.14. It is a crime to drive with a level of 0.08 or higher.

Crapo told reporters that he plans to seek re-election to a fourth term in 2016 and hopes to earn back the trust of constituents.

“Certainly I have to believe it will cause them to be disappointed in my conduct. I don’t blame them,” he said. “I am disappointed in my conduct. I want to be sure they understand that I accept full responsibility for what I’ve done. I am sorry and I will work to regain the trust that I’ve lost.”

Asked to describe the events that led to his arrest, Crapo said, “I was drinking alone at my home and I got into my car alone. I never got out of my car and I was not going to meet anybody. It was simply a drive of frustration. I couldn’t get to sleep and I made the very poor choice that I would go out and go for a drive.”

Crapo said he didn’t know he was impaired when he got in his car, but turned around after realizing he shouldn’t be driving. “I turned back, and that’s when the police officer pulled me over,” he said.

The drive lasted 30 or 40 minutes, he said.

Contrary to an earlier report, Crapo said he was not drinking shots of vodka. “I did mix the vodka with tonic water. I was not drinking straight vodka,” he said.

Crapo said being alone and away from his family shortly before Christmas contributed to his decision to drink that night, a few days after the Senate adjourned for the Christmas break.

He said he had scheduled flights to Idaho for Friday night and Sunday morning, but work kept him late Friday and he couldn’t make it to his Idaho Falls home until Sunday.

Crapo’s wife, Susan, didn’t move to Washington after Crapo’s election to Congress in 1992, remaining in the Gem State to raise the couple’s five children. Crapo served in the U.S. House before joining the Senate in 1999.

Crapo said he has apologized to his family and has their support and encouragement.

“I have a strong marriage, and my wife and I love each other,” Crapo said. “That’s the extent of what I want to say there.”

In a prepared statement, he acknowledged that his drinking was “at odds with” his Mormon faith.

Since his arrest, Crapo has gone about his regular Senate business, voting on New Year’s Day for the fiscal cliff compromise.

If Crapo wins a new six-year term in 2016, it would extend his congressional career to 30 years, longer than any Idahoan’s except the late Sen. William Borah.

“That’s four years off, but I fully intend to run again, as long as there are no family or health concerns,” he said. “And I hope to continue to make a contribution in the United States Senate.”

The suspension of Crapo’s driver’s license applies to Idaho and Washington, D.C.

“I intend not to drive anywhere, period,” he said. “I am frankly going to just have to make arrangements to walk to work or to take cabs or to find other ways to get to the places I need to get to.”

Crapo said he believes he would have stopped drinking even had he not been arrested for DUI.

“I was already thinking in my own mind that this had to end,” he said. “I don't know how to give you a timetable answer to that, but I believe in my heart that I had already recognized that I was on a bad path and that I needed to find a different path to follow.”

Dan Popkey: 377-6438

McClatchy Newspapers reporter David Lightman contributed to this story.