Michael Meehan, Sen. Maria Cantwell’s chief of staff, is reportedly leaving his post after the first of the year. The long-planned yet officially unannounced move is unrelated to yesterday’s news that a Cantwell scheduler was arrested by an undercover FBI agent for allegedly soliciting sex from a 13-year-old boy. Meehan (who according to two sources hired the scheduler) said in a statement that James Michael McHaney was fired Friday: “Our office has and will continue to fully cooperate with the ongoing federal criminal investigation. Senator Cantwell has zero tolerance for crimes against children.”Couldn’t reach Meehan for comment about his plans post-Cantwell. He’s been with the senator’s office off and on since 2001. He returned to work for her in 2006 following a stint working on Sen. John Kerry’s presidential campaign. Meehan isn’t the only former Kerry staffer to leave Cantwell’s office recently. Former Cantwell communications director Katharine Lister, who worked as a Kerry campaign spokeswoman in 2004, left earlier this fall. (McHaney also came to Cantwell’s office by way of the Kerry camp.)Meehan’s replacement is Maura O’Neill, a local PR consultant and longtime Cantwell confidant. Update: Word on the street is Meehan will be joining Governor Christine Gregoire’s re-election campaign early next year.