Here are the election results for the pro-liberty candidates and ballot questions for the 11/6/2012 election in MA that I know of.

Liberty candidates went 3 out of 17 or an 18% success rate. The 3 liberty candidates who won were incumbents. Another liberty candidate who lost was an incumbent.
Statewide liberty ballot questions went 1 out of 2.
There were many local ballot questions. The majority were about increasing property taxes or issuing bonds. Some dealt with other issues like calling for an end to the war on marijuana. Unfortunately, the majority of the local questions passed.

Lost - Libertarian Gary Johnson

Lost - Libertarian Daniel Fishman
US Representative, 6th Congressional District

Lost - Libertarian Robert Underwood
Massachusetts Representative, Ninth Hampden District

The Mass Liberty Caucus candidates:
State Senate:
Lost - Paul Adams, Andover,
Barry Finegold
Dem 44,223 65%
Paul Adams
GOP 23,648 35%

Lost - Tom Keyes, Sandwich,
Therese Murray
Dem 49,615 58%
Thomas Keyes
GOP 35,627 42%

State Representative:
Won - Representative Nick Boldyga, Southwick,
Nicholas Boldyga
GOP 11,672 61%
Samuel Salvatore DiSanti
Dem 7,403 39%

Lost - Susannah Lee, Orange,
Denise Andrews
Dem 8,264 45%
Susannah Lee
GOP 8,084 44%
Richard Schober
Ind 1,906 10%

Lost - Bill McCarthy, Worcester,
Angelo Puppolo
Dem 13,228 70%
Dennis McCarthy
GOP 5,603 30%

Won - Representative Kevin Kuros, Uxbridge,
Kevin Kuros
GOP 10,475 51%
Robert Dubois
Dem 9,972 49%

Lost - Representative Steven Levy, Marlboro,
Jonathan Zlotnik
Dem 8,512 51%
Richard Bastien
GOP 8,181 49%

Lost - Rich Eustis, Medway,
Jeffrey Roy
Dem 11,835 54%
Richard Eustis
GOP 9,961 46%

Lost - Walter Zenkin, Burlington,
Kenneth Gordon
Dem 11,765 55%
Walter Zenkin
GOP 9,536 45%

Lost - Karen Rhoton, North Andover,
Diana DiZoglio
Dem 11,133 63%
Karin Rhoton
GOP 6,555 37%

Lost - Jim Stanton, Walpole,
John Lawn
Dem 10,406 76%
Francis Stanton
GOP 3,290 24%

Lost - Debra Betz, Plymouth,
Thomas Calter
Dem 13,378 63%
Debra Betz
GOP 8,008 37%

Forum poster mz10 mentioned 2 candidates:
Lost - Steven Levy for State Rep 4th Middlesex District
Danielle Gregoire
Dem 9,111 51%
Steven Levy
GOP 8,881 49%

Won - Ryan Fattman for State Rep 18th Worcester District
Ryan Fattman
GOP 13,391 70%
Donald Bourque
Dem 5,729 30%

Ballot Questions:
Failed - Question 2 the Massachusetts Death with Dignity Initiative
Passed - Question 3 the Massachusetts Medical Marijuana Initiative

There were local, non-binding ballot questions dealing with the drug war. All of them were pro-liberty and they all passed.
"Shall the State Senator/Representative from this district be instructed to vote in favor of legislation that would allow the state to regulate and tax marijuana in the same manner as alcohol?" -- won with 69% in the 2nd Middlesex Senate District, 71% in the Middlesex and Suffolk Senate District, and 72% in the 2nd Berkshire State Representative District.

"Shall the state Senator/Representative from this district be instructed to vote in favor of a resolution calling upon Congress to repeal the federal prohibition of marijuana so that states may regulate it as they choose?" -- won with 54% in the 22nd Middlesex State Representative District, 65% in the Essex and Middlesex Senate District, and 66% in 8th Essex State Representative District.

There were dozens of local tax or bond increase issues on the ballot. Maybe 1/2 of the ballot issues were about increasing property taxes. Most of the ballot issues passed but several failed. See the details.

Anyone I missed? If so, let me know.

Source for most of the results