Today, the 21,000-member Massachusetts Sierra Club unveiled their 2008 state legislative endorsements where they waded into several House Democratic primaries and one open Senate race.

The environmental organization says it used candidate questionnaires, interviews and “extensive independent research” to determine who it would back, settling on 53 House and Senate candidates.

Jennifer Flanagan won the endorsement in the open Senate Democratic primary for the Worcester and Middlesex seat while endorsements were not made in the other contentious state Senate Democratic primaries: the 4th Middlesex district, where John W. “Jack” Hurd and Kenneth Donnelly are competing for Sen. James Marzilli’s open seat, and the 2nd Suffolk district rematch between Sen. Dianne Wilkerson and Sonia Chang-Diaz.

Most surprisingly, powerful House Committee on Steering, Policy and Scheduling Chair Paul Donato was shunned in his 35th Middlesex Democratic primary contest, where no endorsement went out. Other incumbent Representatives Anthony Verga (5th Essex), Carl Sciortino (34th Middlesex) and Harold Naughton (12th Worcester) were endorsed in their primaries. The Sierra Club is also staying neutral in the 10th Suffolk House primary, where Rep. Mike Rush faces to challengers.

In the open House primaries, Jonathan Hecht received the group’s backing in the three-way 29th Middlesex Democratic race. Carolyn Dykema in 8th Middlesex and Jason Lewis in 31st Middlesex also got the stamp of approval.

“As the combined threats of global warming and a tightening economy meet with opportunities for economic growth through environmentally friendly opportunities these candidates offer true leadership,” MA Sierra Club Political Committee Phil Sego said in a statement. “All studies show we do not enjoy the luxury of time – these candidates recognize that and want to act appropriately.”

Full list of endorsed candidates:

REPRESENTATIVES (Alphabetical by Last Name)

• Atkins, Cory - Middlesex, 14th
• Balser, Ruth - Middlesex, 12th
• Benson, Jennifer - Middlesex, 37th
• Brownsberger, William - Middlesex, 24th
• Clark, Katherine - Middlesex, 32nd
• Conroy, Thomas - Middlesex, 13th
• D’Amico, Steven - Bristol, 4th
• Dean Campbell - Linda, Essex, 15th
• Dykema, Carolyn - Middlesex, 8th
• Ehrlich, Lori - Essex, 8th
• Falzone, Mark - Essex, 9th
• Grant, Mary - Essex, 6th
• Guyer, Denis - Berkshire, 2nd
• Hecht, Jonathan - Middlesex, 29th
• Honan, Kevin - Suffolk, 17th
• Jackson, Kate, -Bristol, 2nd
• Kaufman, Jay - Middlesex, 15th
• Khan, Kay - Middlesex, 11th
• Kocot, Peter - Hampshire, 1st
• Kulik, Stephen - Franklin, 1st
• Lewis, Jason - Middlesex, 31st
• Mae Allen, Willie, Suffolk, 6th
• Natale, Patrick - Middlesex, 30th
• Naughton, Harold - Worcester, 12th
• O'Day, James - Worcester, 14th
• Patrick, Matthew - Barnstable, 3rd
• Peake, Sarah - Barnstable, 4th
• Peisch, Alice - Norfolk, 14th
• Provost, Denise - Middlesex, 27th
• Richardson, Pam - Middlesex, 6th
• Rushing, Byron - Suffolk, 9th
• Scibak, John - Hampshire, 2nd
• Sciortino, Carl - Middlesex, 34th
• Smizik, Frank - Norfolk, 15th
• Story, Ellen - Hampshire, 3rd
• Sturgis, Ellen - Middlesex, 3rd
• Swan, Benjamin - Hampden, 11th
• Toomey, Timothy, Middlesex, 26th
• Turner, Cleon - Barnstable, 1st
• Verga, Anthony - Essex, 5th
• Walz, Martha - Suffolk, 8th
• Wolf, Alice - Middlesex, 25th

SENATORS (Alphabetical by Last Name)

• Chandler, Harriette - First Worcester
• Creem, Cynthia - First Middlesex & Norfolk
• Downing, Benjamin - Berkshire, Hampshire & Franklin
• Eldridge, James - Middlesex & Worcester
• Fargo, Susan - Third Middlesex
• Flanagan, Jen - Worcester & Middlesex
• Jehlen, Patricia - Second Middlesex
• Montigny, Mark - Second Bristol & Plymouth
• Orozco, Sara - Norfolk, Bristol & Middlesex
• Pacheco, Marc - First Plymouth & Bristol
• Spilka, Karen - Second Middlesex & Norfolk