A review should say if you like a film or not, not you really like a film that you know you "shouldn't".
Read Ebert's review of that death penalty film. He liked the cast. He liked the filmmakers. He hated the plot turn the story took (and the implications of the politics) and gave the complete product 0 stars.
I read Harry Knowles' reviews on Ain't It Cool News. Harry has liberal politics too but I've know Harry and his dad for over a decade. I can tell from his enthusism (or disgust) if a film is usually worth my time or not. It's not foolproof (Michael Weldon at Psychotronic Video Magazine is a better match for my likes. Harry still tends to be enthusiastic over some films that I don't care for (Bowling for Columbine being the least of them) but I think that I've agreed on the films he hated and can at least understand his approval of crap like Charlie's Angels II (he saw it as a string of fetish costume sequences, something for everyone just don't look for a plot).