MIAMI (AP) - After going through rehab for a cocaine addiction and pledging that he'd work through his problems to regain his Florida constituents' trust, Trey Radel's short career in Congress ended with a whimper Monday.
    
Facing a House ethics investigation, a growing group of primary challengers and the steady drumbeat of a Republican establishment calling for him to step down, the 37-year-old, who pleaded guilty to cocaine-possession charges last year, quietly tendered his resignation letter.
    
"Regardless of some personal struggles in 2013, this year has already been tremendously positive as I focus on my health, family and faith," he wrote to House Speaker John Boehner. "Unfortunately, some of my struggles had serious consequences."
    
On Nov. 20, the freshman Republican pleaded guilty to a misdemeanor charge of cocaine possession and was sentenced to a year of probation. He admitted to purchasing 3.5 grams of cocaine from an undercover officer Oct. 29 in Washington.
    
"While I have dealt with those issues on a personal level, it is my belief that professionally I cannot fully and effectively serve as a United States Representative to the place I love and call home, southwest Florida," Radel wrote in the letter.
    
Politico first reported the resignation Monday morning.
    
Several GOP leaders, including Gov. Rick Scott, had asked him to resign. But Radel had pledged to stay in office after taking a leave of absence and completing a monthlong in-patient treatment program for drug and alcohol abuse. In a defiant prime-time news conference last month, he defended his legislative record and pledged to redouble his congressional efforts "with a clearer focus and a stronger mind."
    
After returning to Congress this month, he apologized to Republican colleagues and assured them in a closed-door meeting that he was in a good place and had found a support group, according to House aides who spoke on condition of anonymity at the time because they weren't authorized to discuss the private meeting.
    
Political pressure, however, was building.
    
The House Ethics Committee announced last month that it was launching a formal investigation of the congressman, and at least one of his former rivals, former state Rep. Paige Kreegel, had vowed to challenge him in a GOP primary. On Monday, Scott lauded Radel's decision.
    
"I think he did the right thing for his family. He did the right thing for the state," Scott told reporters in Miami. "I'm glad he's getting taken care of" by undergoing treatment.
    
Meanwhile, the outlines of a crowded campaign to replace Radel in Florida's solidly Republican 19th District began to take shape. Scott will set a date for a special election to fill Radel's seat.
    
Lizbeth Benacquisto, the GOP majority leader of the state Senate, said she was weighing a congressional bid while former Rep. Connie Mack IV, who represented the area for eight years before a failed run for Senate, hinted at a potential run.
    
Kreegel, who announced his campaign earlier this month, said Radel's resignation gives constituents the chance to move on.
    
"Southwest Florida should expect a congressman who can lead, a congressman without distractions, and a congressman they can trust," he said in a statement.
    
Radel had been in office for 10 months when charged. His deeply conservative district includes the Gulf Coast cities of Fort Myers and Naples.
    
The drug arrest derailed a seemingly promising career.
    
After a stint as a TV news anchor, he started a media-relations firm and hosted an early-morning conservative talk-radio show in southwest Florida. He married another news anchor, and they had a baby.
    
When he decided to run for Congress, he became involved in a bruising, six-way GOP primary, openly targeting opponents on the Internet and facing criticism for his firm's ownership of explicitly named websites. But he was backed by the local tea party movement and clinched the GOP nomination. Supported by Republican luminaries, including Mack and Sen. Marco Rubio, he cruised to victory in November.
    
Things seemed to be going well for Radel. His wife was featured in a glowing local news segment about how the couple was adjusting to life in D.C. He sponsored a handful of bills and was interviewed by several inside-the-Beltway publications. He was active on Twitter and championed cuts in sheep-farm subsidies, keeping good on his conservative promise.
    
Then, on Oct. 29, Radel attempted to buy $250 worth of cocaine from an undercover police officer in a Washington neighborhood.
    
According to court documents, federal agents confronted the congressman and he invited them to his apartment, where he turned over a vial of the drug. A DEA official who spoke on condition of anonymity because he was not authorized to release details of the case in his own name said Radel was identified to authorities as a cocaine buyer by his suspected dealer.
    
For the next three weeks, Radel didn't skip a beat. He held a re-election fundraiser at a Naples country club and continued to cast votes. He did not tell House leaders about the bust until Nov. 19, when reporters broke the news about the case.
    
When his arrest became public, Radel said during a news conference that he had struggled with drug and alcohol abuse "off and on for years."
    
While court documents said the lawmaker purchased cocaine on several occasions before the October incident, he maintained that he had used the drug only "a handful of times." His treatment, he said, was focused on alcoholism.
    
On Monday, Radel thanked Boehner and his colleagues for their support and said he is leaving Congress "with friendships and memories."
    
"As an eternal optimist, I know there are great things in store for our country when we find ways to work together," he wrote. "Whether it is as a father, a husband, or in any future endeavor, I hope to contribute what I can to better our country in the years to come."


In response to Radel's news, Congressman Connie Mack issued the following statement:

"Trey's decision to resign from Congress was undoubtedly very difficult, but it was the right decision. Trey's been a friend for many years, and I just can't imagine how difficult this situation has been for his entire family. All of us wish Trey and Amy nothing but the best moving forward.

"Now it's time for Southwest Florida to elect a new Congressman who will be a tireless champion of our shared mainstream conservative values. We must begin to solve the real long term  challenges facing our country, including restoring fiscal discipline to our politics and our policies. That includes being a staunch advocate for the Mack Penny Plan which would cut spending and balance our budget in a common-sense responsible manner. The people of Southwest Florida and the nation deserve nothing less."

Governor Rick Scott had the following to say:

"I believe that Trey is making the right decision for him and his family. I'm glad he has sought help, and it's my hope he continues to put his attention on rehabilitation and his family."

Senator Lizbeth Benacquisto also issued a statement: 

"Today I want to recognize and commend Trey for making the right decision. He has acknowledged that his recovery requires a focus solely on his health and the well being of his family. Trey, his wife Amy, and their precious son have been and will remain in my prayers. This announcement also makes it clear that Southwest Florida families will soon choose a new voice to represent them in Congress. I will consider the best way I can be of service to Florida and our region. This includes talking to my neighbors, my friends, and my family to seek their guidance moving forward."

State Representative Paige Kreegel sent the following remarks:

"I know the last several months have been trying for Trey and his family. But today, he did the right thing for the people he represents and provided all of us a chance to move forward without the distractions of the past. The people of Southwest Florida deserve principled, conservative leadership. That’s why I announced my candidacy a few weeks ago and began my campaign to bring that type of leadership back to the 19th District of Southwest Florida. From ObamaCare, to Washington’s out-of-control spending, to the breaches of national security, the issues facing our country are serious matters that deserve serious representation. Southwest Florida should expect a Congressman who can lead, a Congressman without distractions, and a Congressman they can trust. As I’ve stated before, character and integrity still matter in politics. It’s not the mistakes a person makes but how they handle those mistakes. I want to thank Trey for his service and wish him well in whatever path his future holds. It’s time to move forward. I will focus on common-sense solutions that are based on conservative principles and conservative values."

Lee County Sheriff Mike Scott released this statement:

"As I have said from the onset of this situation, I support Trey Radel personally and wish the best for him and his family. I believe that his decision to resign is the right thing to do, and I look forward to better days for Congressional District 19."