There is a phenomenon I've observed in our culture that is not restricted to a single arena. It is the situation wherein you hold a differing opinion than some of those around you, and they simply cannot handle that. They must set upon you like starving Dingos to persuade you to their point of view, discourage you from further voicing your thoughts or to marginalize you in the ideological landscape. The notion that you might thinking differently than they do cannot be tolerated (in contrast to the "tolerance" supposedly valued by the those same people). There's a sense in which they hold the "orthodox faith" in a specific category, and you are the unrepentant "heretic." As a result, sharing your thoughts on a matter can be risky business - even among those you call "friends" (facebook's redefining of that term notwithstanding). To this end one must be prepared: if you share your thoughts on a matter, and it deviates from the "party line," you may be required to debate your point with nauseating endurance by those unwilling to simply let you have your view.
It is because I have no appetite for debating, arguing and rhetorical "combat" that I now have learned to keep many viewpoints to myself. Those around me that have constituted that "swarming Piranha" can glory in their triumph for having successfully intimidated someone into keeping his opinions (for the most part) to himself.
I find this prevalent in two arenas (though there may be others): politics and religion. In both of these, the propensity for debate and argument is strong. Ever since preaching replaced "the table" as the primary "sacrament" of the Protestant church, the art of speech as a persuasive enterprise has permeated throughout not only Western Christianity, but politics as well. Prior to The Democratization of American Christianity, personal views would have appeared more tolerable because (1) kings did not have to persuade subjects to vote for them every few years, and (2) pastors did not have to persuade people to remain in their church. However, as western culture has progressively moved toward the necessity to persuade every individual, the rise of the opinionated person has become so commonplace as to nearly constitute a next "phase of evolution." As a result, anyone with a strong opinion is (or has to be) in "persuasion mode." I'm seen as a "preacher" for my viewpoint, proclaiming forth the "correct" perspective and shouting down all opposition.
In the religious arena, my experience has been that the fundamentalist mentality will not countenance a differing viewpoint. It's never enough how much in common you might have with someone in the same broader faith context. On the contrary, the differences (no matter how slight) are cause for their alarm; to the extent that they will "root out" the deviant within their midst. It is not enough to hold in common the same basic tenets of faith, particularly in regards to (in my case) historic Christianity. No, the manner in which your smallest opinion differs from mine must be discovered and camped on until it's all we talk about. It's the most important thing I know about you, and the major issue in which I need to convince you to think the way I do. Whether or not you like me or can stand my presence is of no consequence; your complete agreement with me is all that matters.
Such is it in political discussions as well. I am sure that there exists plenty of this type of person on both sides of the political spectrum, but because I am a "conservative" (with "libertarian" tendencies), I've experienced it mostly from those on the ideological "left." Post any opinion or share any idea regarding my distaste for government expansion, the eroding of personal responsibility or monstrous taxation, and "it's on." It is not enough for those friends or acquaintances of mine that fit well within the "liberal" or "progressive" category to simply shake their heads and think, "There he goes again." No... their biting comments are nearly inevitable. Not content that my view differs from theirs (even thinking me misguided), my view must be "shot down" with righteous fervor and forceful argumentation. It is simply intolerable that I might have a different opinion. It is not enough to subscribe to a different political philosophy, my view must be demeaned and mocked with biting jabs until I finally "shut, the heck, up."
Well, to all of my debaters and arguers, I raise a glass in your victory. I am successfully intimidated. You win. I am now, by and large, fearful of posting anything on facebook or twitter regarding politics, government, or those goofy ideas you hold about "how many Angels can dance on the head of a pin." Since I'm so confident I'll never persuade you either, I'm not going to waste energy trying. I'll simply vote how I vote, worship how I worship, and hopefully raise children that are pretty reasonable too. But around you, I pretty much have no opinion. Why? Because it's just not worth expending the energy to endure the onslaught of your intolerance. Congratulations... My silence is your glory (and the saddest part is, I'm sure you think so).