What idie films do so well

is create well-rounded dimensional characters.

People who go to this movie expecting a tradional comedy will be disapppointed. There are some funny lines and humorous situations, but there's a lot more to the story.
Grant Cogswell is almost as much villain as hero. As played by Joel Moore, Cogswell is emotionally immature and volatile, and he has no real plan for city council other than opposing the expansion of the light rail. His story arc ends up a circle.
Phil Campbell is another man-child partly stuck in frat-boy mode. He actually seems to learn something from the experience.
Cedric the Entertainer's Richard McIver comes across as a likeable decent man who is genuinely shocked and hurt by attacks on his record and motivations.

All the actors give subtle nuanced performances, shading their characters, bringing them to life.

Hollywood would have turned the characters into caricatures, and produced more broadly written scenes. Here we have an example of what indie film makers do so much better than mainstream Hollywood.

This isn't a laugh out loud comedy or a tear-jerking drama, but a "slice of life" film. Expect something different from Grassroots; expect something more.