CRANSTON, R.I. (AP) — Gov. Lincoln Chafee is not running for a second term, he said Wednesday in an announcement that surprised his political opponents and closest advisors alike and takes him out of what was expected to be a fierce primary in his new Democratic Party.

The governor, who became a Democrat in May, has struggled with poor approval ratings and is a reluctant fundraiser, although he said on Wednesday he liked being governor and thinks he would have won re-election. But he described campaigning as hugely time-consuming, and said the state faces so many serious challenges that he wouldn't be able to effectively be governor and run for governor at the same time.

"I enjoy the challenge of combat. But I also enjoy the challenge of running a government, and in this moment of Rhode Island's history, I want to put all my time, all my energy, to the task at hand. And that is running our government," Chafee said.

The governor said he told his staff Wednesday morning. But many people close to the governor who were contacted by The Associated Press before the hastily assembled 2 p.m. news conference held outside the Department of Motor Vehicles said they had no idea he was announcing anything. One staffer who attended the event said he didn't know why he was there.

Chafee is a former Republican and was the most liberal one in the U.S. Senate when he succeeded his father, the late John Chafee, in 1999.

Lincoln Chafee lost his Senate seat in 2006 to Democrat Sheldon Whitehouse, became an independent in 2007 and won a four-way race for governor in 2010.

His switch to the Democratic Party set up what would have been a divisive primary against expected candidates Gina Raimondo, the state treasurer, and Providence Mayor Angel Taveras.

Both praised the governor, with Taveras calling him "a man of integrity" and Raimondo saying he "always had Rhode Island's best interests at heart and was an unfailing optimist during very difficult times." Chafee said he would not endorse anyone in the primary.

Rhode Island has struggled for years with a bad economy and high unemployment.

Chafee on Wednesday listed among his accomplishments a decline in the unemployment rate from 11.5 percent to less than 9 percent, something he said was still unacceptable and he wanted to work on. He also cited reducing wait times at the DMV from hours to 20 minutes, increasing aid for education and seeking to recoup taxpayer losses from the state's failed investment in Curt Schilling's video game company, 38 Studios.

Chafee did not rule out seeking political office again and said he came to the decision after discussing it for months with his family. A vacation last month in Maine — and two long drives there and back with his wife, Stephanie — helped him decide, he said.

He said that opting not to run was separate from his decision to switch parties.

Chafee said when he became a Democrat that "joining a team" would allow him to collaborate with the Democratic governors in neighboring Connecticut and Massachusetts. A longtime political ally of President Barack Obama, he also said it would help him raise money for his bid for a second term.

But Chafee does not like to fundraise and had just $377,000 in his campaign account as of June 30, according to a filing with the Rhode Island Board of Elections. He has poured millions of dollars of his own wealth into his past campaigns. Raimondo had more than $2 million in her campaign account, and Taveras had just under $700,000, according to filings.

Chafee spokeswoman Christine Hunsinger said money had nothing to do with Chafee's decision, and that he would have been competitive on all fronts if he had run.

Brown University political science professor Wendy Schiller said Chafee's move paves the way for what she called a titanic battle between Raimondo and Taveras. She said Taveras probably gains more by Chafee dropping out, as he would have competed with the governor for the support of organized labor. But Schiller also said Raimondo may be able to gain the backing of women voters previously in Chafee's camp.

Neither Taveras nor Raimondo have formally announced their plans.

Chafee said his late father, who also served as governor, would support his decision to stand aside. John Chafee always used to say you should leave things better than you found them, the governor said.

"It's a good decision," Chafee said his father would say. "Rhode Island's got its challenges. Put your nose to the grindstone, and take care of the issues."

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