There is no mystery which Democrat will succeed Sen. Paull Shin in the state Senate.

Rep. Marko Liias has been the only person seeking the vacancy created when Shin resigned Jan. 7 after being diagnosed with Alzheimer’s disease.

Liias is expected to be formally nominated Saturday by Democratic precinct committee officers in the 21st Legislative District and officially appointed Tuesday by the Snohomish County Council.

Then the 32-year-old Liias will pack his bags in the House, where he’s prospered the past six years, and resettle in the Senate, where it won’t take long for his liberal beliefs and partisan inclinations to emerge.

Democrats voting Saturday already know where the aspiring and loquacious pol is coming from. Here’s what the soon-to-be-senator wrote to them:

“Over the last year, we have seen the Senate change hands from a Democratic majority to a Republican-led coalition. Too often, Tea Party extremism and gridlock have prevented important action on the issues that matter to middle class families across our state. I am asking for your nomination as our next senator to change that.”

While there’s an absence of intrigue for the Senate appointment, there is a bit of suspense surrounding the selection of a successor to Liias.

Three people are seeking the House appointment: Lillian Ortiz-Self, Susan Phillips and Darrell Chapman. Under state law, their names will be forwarded to the Snohomish County Council for consideration.

What Democrats must decide Saturday is who will be their first, second and third choices to represent the district, which includes Mukilteo, Edmonds, Lynnwood and south Everett.

Ortiz-Self of Mukilteo is the odds-on favorite to garner the most votes. She’s been campaigning for the seat since October. That’s when Shin first announced he intended to retire at the end of 2014 and Liias declared he’d run for the seat.

A middle-school counselor and member of the Washington Commission on Hispanic Affairs, Ortiz-Self has been endorsed by several state lawmakers inside and outside Snohomish County. She’s also reportedly made a strong impression on House Speaker Frank Chopp, D-Seattle.

Chapman, of Edmonds, can boast a long record of serving the party and helping elect Democrats into city, county, state and federal offices — including many of those backing Ortiz-Self.

He’s president of the Snohomish County Labor Council and political director of the International Brotherhood of Electrical Workers. But that solid foundation may not be solid enough come Saturday.

Phillips, of Edmonds, is the wild card. She entered late and has been the least involved in partisan activities of the three.

As the president of the Edmonds School Board, she’s the only one with experience winning an elected office. Appointed to the school board in 2007, she’s won twice — in 2009 and again in November.

It will be an interesting time Saturday, and the mystery will be solved next week.

–Political reporter Jerry Cornfield’s blog, The Petri Dish, is at www.heraldnet.com Contact him at 360-352-8623 or jcornfield@heraldnet.com