Washington will have a new governor in 2013.

Two-term Democratic incumbent Chris Gregoire made it official Monday, telling reporters on the front porch of the Executive Mansion that she won’t seek a third term in 2012.  She talked about “amazing triumphs and difficult challenges,” and said stepping down is “the right decision for me and my family.” Her news, no surprise to politicos, means a wide-open governor’s race for the first time since Gary Locke stepped aside after two terms and anointed Gregoire as his favored successor.

Republican Rob McKenna, who succeeded Gregoire as attorney general in 2005, kicked off his race for governor last week. Gregoire’s apparent favorite to be her successor, Congressman Jay Inslee, got advance word of the governor’s decision — and her encouragement.  Inslee says he’ll have something to say soon.  Others from both parties may also chime in.

Secretary of State Sam Reed, the state’s chief elections officer, said the state can look forward to a lively race for governor, possibly one of the most competitive in America.  He said:

“Our best wishes are with Governor Gregoire as she finishes her last 18 months in public life, reflects on her accomplishments during some challenging times, and looks forward to the next phase of her life — a well-earned retirement, the private sector or continued public service.

“Over the coming months, we look forward to hearing a civil and positive campaign by our governor candidates.   The voters want more than sound bites, attack ads and negativism. Our state expects and deserves an honest and substantive discussion of the issues facing our people and how the candidates would solve problems and provide leadership.”

A reminder: Under the Top 2 Primary system, voters collectively will choose their two favorite candidates in August of 2012, without regard to party preference, and those two will advance to the November ballot.  The parties are not guaranteed a runoff spot. Candidates officially file for office beginning May 14 next year, although they must file with the Public Disclosure Commission immediately upon announcing their candidacy, and produce regular reports of contributions of income and expenses.