These people definitely don't represent the majority of people in your district but even 3/10 people living there have a progressive worldview is more than enough to swamp a town hall with sufficient turnout.
Olinsky in a nutshell. They may not be truly representative of the district as a whole, but because they're the ones "making the noise" they're the ones that get the attention. Too bad for those activists that after 8 years of Obama, Republicans are aware of that game, and know full well that even the Tea Party did comparable things to the Dems in more than a few districts. (Only they managed to unseat more than a few, where it turned out, the Tea Party was more representative of the district than the Democrats wanted to believe)
I don't support their behavior though, I find have a personal theory that large groups of angry people (or large groups protesting) are inclined to act as a group much more like the biggest idiots/jerks in the group instead of the most informed and reasoned people in the group.
Well, based on the kind of press they obtained locally, their best tack is not try it again, local press is not sympathetic, and is going to generate a narrative that will make them look like an enemy people in the district need to rally
against, rather than the other way around. That they're starting out with a position that isn't close to mainstream for the area/district to start with just makes things even worse for them from there.
Labrador was a bad choice anyway, he's already said he isn't running for the US Congress again in 2018, so good luck have fun with making him think he won't get re-elected if he doesn't change his stance.
..Of course, he is considering a Gubernatorial run currently, but once again, in that respect, his current district(1st Congressional) is the "ultra-liberal" district in Idaho, at least it was the last district in the state to send a Democrat to congress (for a single term in office) since Bill Clinton became President...