Sometimes I think the most important thing we can do keep ourselves politically healthful is to remember the existence of extremists -- both near and far from our own positions.
It's important to remember the extremists whose positions are (relatively) near one's own -- that is, persons who take the extreme version of your "side" of a given political contest -- in order to guard against the allure of purism. Being pro-Israel for example, one ignores or downplays the existence of pro-Israel extremists at one's own peril. It important to remind oneself that it is not better to adopt ever-more fundamentalist or uncompromising iterations of one's own position, and you are not a failure or a traitor for refusing to fall onto that path. Recalling and recognizing those who speak under your banner but do so in a destructive or harmful way can help dissipate some very dangerous temptations and forestall one from excusing things that are fundamentally inexcusable.
It is also important to remember the extremists whose positions are on the far side from one's own -- if only so one is not surprised by them when they inevitably do emerge. Particularly if one is feeling frustrated with one's own camp, there can be the temptation to romanticize one's opposition; going beyond the (important and correct) refusal to generalize and demonize and instead allowing oneself the delusion that there is no dangerous politics on the other side of the rainbow. The delusion is bad enough, but the real damage comes when one is forced to confront the reality -- if one isn't prepared, it is a shock of cold water that can quickly trip the unwary into spiraling down their own path of extremism. I can't tell you how many videos and screenshots I've seen from "pro-Israel" Twitter displaying the worst of terribleness from various pro-Palestinian rallies or protests, all of which style themselves as trying to shock complacent Jews out of their purported stupor. And indeed, if one hasn't prepared yourself to encounter it, it is quite a bracing sight to behold. But for my part, since I've never deluded myself that this sort of anti-Zionist extremism did not exist, I was never unduly shocked when confronted with its manifest existence.
Keeping these things in mind allows one to keep one's head on a little straighter. Instead of retreating to pathetic denials that this sort of abhorrent politics is present, or opportunistic romanticism of why it's actually permissible or just, remembering and acknowledging the genuine existence of extremism allows one to keep a sense of perspective. Being able to name and recognize extremism as part of the story also allows one to keep a sense of proportion that it is not the entire story.
No matter your ideology, there will always be someone profoundly idiotic who largely agrees with you, and someone profoundly idiotic who largely disagrees with you. Neither fact should be unduly weighted.