Dick Dadey, executive director of the good-government group Citizens Union, said the Legislature's failure to agree on district lines changed everything in 2012.
"They couldn't get a law with these new lines to the governor," Dadey said. That gave a group of voters the opportunity to go to federal court and for the court to remake the maps statewide.
Susan Lerner, executive director of Common Cause New York, said the next key was giving the court rational alternatives that could stand up to objections from lawmakers.
"It's because Common Cause and the civil rights groups had strong maps," she said. "There were valid, objective maps the court could use."
In the end, the Legislature chose not to challenge the court-drawn districts.
Lerner said the result was more competition. The election included the defeats of three first-term incumbents: Democrat Kathy Hochul in western New York and Republicans Nan Hayworth in the Hudson Valley and Ann Marie Buerkle in central New York.
It also saw the first Asian-American elected to Congress from New York, Queens Democrat Grace Meng.
The previous drawing of lines to dilute the power of minority groups was an issue addressed in the 2012 process, Lerner said. That included Meng's predominantly Chinese neighborhood.
"Certainly it gave her a better opportunity," Lerner said, stopping short of fully attributing Meng's victory to the new district lines.