Have you ever noticed that, when someone comes close to an ideology without quite matching it, they get dumped on hard by members of that ideology? Example: "mainstream GOP" being crapped all over by the tea party. Or, for that matter, the way sectarian violence overshadows inter-religious violence? If you were a Lutheran or a Calvinist in 1630, you weren't worried about Muslims, you were worried about Catholics.
A number of years ago, I was tossed out of the Arizona democratic party. My card was invalidated, and I got a nice letter saying how I wasn't "on message". This was because I argued that the dems should stop pushing gun control, and I had mentioned that I don't give a damn about Palestine. Never mind that I am a huge supporter of single-payer health insurance, SSI, SNAP, Gay marriage, and just about every other item on the agenda.
I don't mind being tossed, really. I didn't like them anyway. But the fact is, you can automatically assume that the most vitriol aimed in your direction will come from people that are very close to you on the issue at hand, not the people on the other side of the aisle.
I call this the "traitor complex". It occurs when people have their uniform buttoned up so tight that it interrupts the blood flow to their brain, causing them to rage out the moment anyone seems to be drifting away from the strict message represented by the uniform. An outright enemy is a given, and can be accepted as such, but a heretic must be purged.
Example closer to home:
Back during the privilege arguments, some people referred to other PDers as "Part of the Problem", which is fucking ridiculous on any scale. Someone who hasn't thought things through says "women should probably learn self-defense", and suddenly THEY are part of the rape culture. Shit, they're WORSE than the guy dropping rophynol in some girl's drink, or at least the EQUIVALENT, because they didn't understand part of the problem. And then the same people that do this sort of shit shake their heads in disgusted amazement that people actually listen to Rush Limbaugh when he calls feminists "feminazis". Of course the people called "part of the problem" don't run out and become dittoheads, but they probably aren't an ally anymore, either. They tried to help and got their heads bitten off for it, so they just walk away, when an actual EXPLANATION would have solidified their support.
There are two reasons that this happens. The first is that when people look for enemies, they look for them close to "the border". Enemies in direct proximity. This means that they see the very worst case when looking at someone who isn't in complete agreement.
The second comes back to huffing farts under the blanket. The ideologue sees the heretic as a means to increase his or her standing with the other fanatics under the blanket. Pointing out that the heretic is "part of the problem" allows them to gain standing with the fart-huffing crowd.
There's no real excuse for this sort of behavior in Discordianism.