AUGUSTA – Democratic State Committee members are expected to gather this weekend to elect a new chairman of the Maine Democratic Party.

Incumbent Ben Dudley, a former legislator from Portland, recently announced he would be stepping down. Heading into Sunday’s state committee meeting, two candidates were most frequently mentioned as possible successors.

One is the Hancock County party chairman, John Knutson of Brooklin, party officials said. A second, according to party officials, is Eric Mehnert of Orono, who unsuccessfully sought the party’s U.S. Senate nomination last year.

Dudley’s pending departure from his party post was announced last month.

Last week, the Maine Civic Engagement Project, also known as Maine Blueprint, announced it was hiring Dudley to become executive director.

This weekend’s Democratic State Committee election to replace Dudley is expected to be held Sunday afternoon at Augusta City Hall.

With national presidential campaigns well under way and congressional campaign activity in Maine picking up, organizational shake-ups have marked both of the state’s major political parties in recent months.

In April, four months after his election as chairman of the Maine Republican Party, former five-term legislator Joe Bruno of Raymond said he was stepping down, with the party’s vice chairman, Mark Ellis of Augusta, assuming the top job.

Presidential campaign activity in Maine so far has been light. Sen. John McCain has picked up endorsements from Sens. Olympia Snowe and Susan Collins, along with former Gov. John McKernan, who is married to Snowe. Democratic Gov. John Baldacci, the titular head of the state party, hasn’t named a favorite.

But already warming up is the next contest down on the 2008 ballot, as Republican Sen. Susan Collins faces a re-election challenge from Democratic Rep. Tom Allen.

Multi-candidate fields of Democrats and Republicans, meanwhile, are lining in hopes of succeeding Allen in Maine’s 1st Congressional District.

Democrats expressing interest in succeeding Allen include former legislator and national Common Cause President Chellie Pingree of North Haven, former legislator Michael Brennan of Portland, Portland lawyer Adam Cote, York County District Attorney Mark Lawrence, who is a former state Senate president, and state Sen. Ethan Strimling of Portland.

Pingree ran unsuccessfully against Collins in 2002. Lawrence lost when he tried to unseat Snowe in 2000.

On the Republican side, recently resigned federal Small Business Administration regional chief Charles Summers of Scarborough has launched a campaign for the 1st District seat and will be depending on his wife, Ruth, to act as his surrogate while he is on active duty in the military. A former state legislator and congressional staffer who unsuccessfully ran for the U.S. House in 2004, Summers is a Navy lieutenant commander recalled for duty in Iraq.

Also eyeing the race for the Republican congressional nomination in southern Maine are businessman Dean Scontras and Steve Abbott, who is Collins’ top aide in the Senate.

No prominent Republicans have signaled interest in challenging Democratic U.S. Rep. Michael Michaud in Maine’s 2nd Congressional District.