U.S. Sen. Evan Bayh said Sunday he won't seek a return trip to the governor's office in 2012.

"After careful consideration, I have concluded that the appropriate decision is not to be a candidate for governor of Indiana in 2012," Bayh said in a prepared statement.

The 54-year-old Indiana Democrat didn't run for a third term in the Senate in November. His seat was won by Republican Dan Coats.

Bayh, of Indianapolis, served two terms as governor, from 1989 to 1997. Many Indiana Democrats had hoped a Bayh candidacy for governor in 2012 could begin reversing a string of setbacks for their party.

The governor's office comes open in 2012 as term-limited Republican Mitch Daniels will be leaving.

"I've been flattered by the speculation about me running for governor in 2012," Bayh said. "I was honored to serve as our governor for eight years. It was a job I cherished every day. Working with a wonderful team, we established a record of creating jobs, cutting taxes, balancing the budget, improving education, reforming welfare and much more of which I am very proud."

Bayh said the main reason for the decision is the well-being of his twin sons.

"As I've said since the day my children were born — when I was governor — my most important job is being a good father. My boys are now in high school, and in my judgment, a run for governor at this time in their lives would be potentially very disruptive."

A centrist whose father, former Sen. Birch Bayh, lost to Dan Quayle in 1980, the younger Bayh first took office in 1987 as secretary of state. That led to a successful 1988 bid for governor that ended 20 years of Republican control of Indiana's top office.

"Another factor in my thinking is whether I want to be in politics my entire life," Bayh said Sunday. "I've been privileged to be in elective office for 22 years and was first elected when only 30 years old. Serving the people of Indiana has been the honor of my life.

"But as I said when I announced my retirement from the Senate, there are many honorable ways to contribute to society — creating jobs, growing a business, helping guide an institution of higher learning, or helping run a worthy charitable endeavor. I'll continue to serve, but my contributions will take a different form and on a different stage."

Indiana Democratic Chairman Dan Parker told The Indianapolis Star that Bayh's departure leaves a void at a tough time for the party.

"Our Moses, who led us to the promised land, has announced he's not going to lead us back to the promised land," Gregg said. "He made Indiana a two-party state. He showed Republicans and independents and Democrats that Democrats could win. He showed the state that Democrats could govern, and govern responsibly and successfully. That was something that hadn't happened in a generation."