U.S. Sen. Olympia Snowe shocked the political world when she announced in February that she would not run for re-election, citing gridlock and an increasingly polarized climate in Washington.

Her decision shined a national spotlight on the corrosive partisanship in Congress and opened the door for former Gov. Angus King to run as an independent and win her seat in November.

Snowe’s decision to step down after 34 years in Congress — 16 years in the House and 18 years in the Senate — and King’s subsequent victory to succeed her have been named Maine’s top story of 2012 by The Associated Press.

The runner-up in the AP’s yearend survey was the legalization of same-sex marriage in November’s election. Voters approved a referendum allowing gay marriage three years after overturning a law allowing it. The state joined Maryland and Washington to become the first states to pass same-sex marriage by popular vote.

In the No. 3 story, Democrats swept back into power in the state House and Senate in November’s election two years after losing legislative majorities to Republicans. The shift in power followed two years of Republican control during which GOP lawmakers rolled back social programs and implemented tax cuts opposed by Democrats.

Democratic control represents a new political dynamic in Augusta, with GOP Gov. Paul LePage no longer enjoying the support of a Republican Legislature.

The upscale town of Kennebunk drew unwanted international attention when a Zumba instructor was charged with turning her fitness studio into a place of prostitution and secretly videotaping clients. The story ranked No. 4. Alexis Wright, 29, and her alleged business partner await trial on prostitution-related charges.

Ron Paul supporters took over the Maine Republican Party state convention and later created a ruckus at the GOP national conven- tion in the AP’s No. 5 story of the year in Maine. With backers of the Texas congressman taking charge at the chaotic state convention in May, a slate of Paul supporters were chosen as delegates to the GOP national convention.

At the national convention, some Paul delegates protested the loss of some of their seats by walking out of the convention and wearing clothespins on their noses.

A huge and likely recordbreaking haul of lobsters caused a market glut, a crash in wholesale prices and tensions to boil over in the No. 6 story in the state.

With Maine fishermen catching huge amounts of lobsters, Canadian lobstermen angrily blocked truckloads of Maine’s catch from being delivered to processing plants in Canada, blaming Maine for low prices and demanding that processors stop accepting Maine lobsters. In the end, processing operations resumed after a Canadian judge issued an order restricting the protests, allowing Maine lobster dealers to resume shipments to Canada.

The USS Miami nuclearpowered submarine sustained $450 million in damage after a Portsmouth Naval Shipyard worker set fire to it while it was in dry dock undergoing repairs. Casey James Fury, 24, has pleaded guilty to arson and awaits sentencing in the No. 7 story of the year. Despite the extensive damage, the Navy says the sub is going to be repaired rather than scuttled.

Thousands of Mainers were removed from the state’s MaineCare roles after the GOP-controlled Legislature changed eligibility requirements. The AP ranked it the No. 8 story of 2012. In his effort to cut state spending, the governor proposed revamping the state’s Medicaid program, known as MaineCare, and eliminating other services and programs administered by the Department of Health and Human Services.

In the No. 9 story, a 10-yearold girl became the youngest person to be charged with homicide in Maine in at least 30 years — and possibly ever — when she was charged in the death of a 3-month-old baby who was staying overnight in the girl’s home in Fairfield in the care of the girl’s mother.

Warm weather made the news throughout the year and was its No. 10 story.

Last winter’s warm temperatures and lack of snow contributed to a dismal season at Maine’s ski resorts, and was blamed for a strong early lobster harvest that created turmoil within the industry. Ocean water temperatures hit record highs off the Northeast for the first half of 2012; scientists said it’s unclear if the warm temperatures, which affect virtually all ocean life, will be a long-term anomaly.

And while Maine was spared the worst from Superstorm Sandy in October, some scientists were concerned that warming temperatures could drive more hurricanes and tropical storms farther north toward New England and Maine in the future.

Other top stories

Some high-profile crime stories also received votes.

In Bangor, two out-of-state men face murder charges in connection with the deaths of three Mainers who were shot and left in a burning rental car on a parking lot in August. The victims — two men, ages 26 and 28, and a 24- year-old woman — were from towns outside of Bangor.

In another triple death, police say 43-year-old Scott Reed stabbed his estranged wife to death in November in the Alton home where she was living before he later returned to the home and committed suicide with his best friend as part of a suicide pact.