If you were in Ontario, i'd say that they don't keep -any- of their campain promises *koffkoff im looking at you mr.mcguinty*, but somehow i dont think that its -only- the Liberals that do that

Maybe that they're generally not tough enough on crime, and the flexible thing could be a negative as well since that can appear to be 'flip-flopping' on the issues to try and get more votes. I'm not sure what their environmental stand is either - likely not as strong as the Green party

Maybe this will help?
A description of Liberal parties in general (worldwide):
http://en.wikipedia.org/wiki/Liberal_party

Liberal party of Canada:
http://en.wikipedia.org/wiki/Liberal_Party_of_Canada
(seems to have lots of info here, but im too lazy/busy/tired to read it all )
Not sure where in Canada you are, but theres links for individual provinces as well.