I am an unapologetic liberal. Or, as liberals tend to call themselves today, "progressive." While I don't agree with the liberal consensus on every little thing, I'm overwhelmingly supportive of liberal causes and ideas. There was a time when I would have called myself "middle of the road," but two things happened to change that. For one, the "road" veered right, leaving me farther to the left of it, and for another, age has had the opposite effect on me that it is said to have on people: it has made me more liberal in my views.
That said, I can't help but cringe sometimes when I visit progressive websites. Just as I'm sure there are many conservatives who hold their heads in their hands when they see the loonies on Fox News, I often find myself rolling my eyes at some of the items I see on liberal sites. Without going into specifics (because I don't want to get caught up in them, since they are not the point here), I'll see people defending behaviors by members of the progressive "team" for which they would have derided conservatives. I see people using extremely flawed logic and straw men to make arguments, and then basking in the echo chamber of righteousness. I see people overstating a case, making things far more black-and-white than they really are, or distorting information to fit it into their argument, blurring the line between fact and opinion. And if you call them on it, they say, "Well conservatives do it too!"
The most powerful arguments are ones backed up by facts. They don't appeal to authority or to some nebulous concept of "common sense." They flow logically from evidence, making as few suppositions as possible along the way. Unfortunately, despite being more powerful, such arguments are, the vast majority of the time, unsexy. They lack in superlatives and generally come across as half-measures to both sides in a debate.
Look, any argument will have opinions and interpretations in it. No answer is so straightforward that it can be arrived at through pure reason. Science is messy and has to make due with real world situations. Not everything can be tested in a randomized controlled trial. But it really gets to me when people build assumptions on top of one another and treat those sets of assumptions as fact.
It's been suggested before that language developed not to communicate truth but to win arguments. If that's the case, then I guess this is a lost cause. But I do wish that people would care less about winning the argument and more about reaching a truthful conclusion.