Yes, there are some evil Republicans and stupid Democrats, just as there are some evil Democrats and stupid Republicans. But the vast majority of supporters of both parties are neither stupid nor evil. And all of them are human. Republicans are neither more nor less likely to be stupid or evil than Democrats.
There's a disturbing tendency among many partisans to dismiss the very humanity of someone merely for holding a different political belief. Not just disagreeing with the relevant differences, but to reject the possibility that someone holding a differing political belief is worth interacting with.
This sort of irrational hate-fueled prejudice is every bit as stupid and disgusting as racism, sexism, or homophobia. I'm sure some who are eager to miss the point will object that people choose their political beliefs, while they don't choose their skin color, gender, or sexual preference. So let's compare political prejudice to anti-semitism.
Religious Jews choose their religious beliefs, just like everyone chooses their political beliefs. (The term "Jew" or "Jewish" can also refer to a culture or an ethnicity, but in this context I'm talking specifically about those who practice the religion.) Unless you're a religious Jew yourself, you think religious Jews believe something that is factually false. And this belief you disagree with is hugely important to their identity as well as yours. From your perspective, they're either denying the true God or proclaiming a false God. That says a lot more about who someone is than what they think about Iraq.
Yet no decent person would proudly proclaim that they refuse to associate with Jews, that they hate Jews, or that Jews are stupid. Sensible people rightly recognize those sentiments as vile and irrational, highlighting flaws in the person expressing them rather than revealing any meaningful truths about Jewish people.
So how is it any different when a hate-filled liberal proudly proclaims their irrational prejudice against conservatives, or a hate-filled conservative proudly proclaims their irrational prejudice against liberals?
It's not. It's only that most people understand why religious prejudice is bad, but far fewer understand why ideological prejudice is bad.
If you're planning to make a blanket statement about Democrats or Republicans, Conservatives or Liberals, think about what the equivalent statement about Jews would sound like. If you want to say, "Democrats think abortion is okay, but I disagree," or "Republicans support the war in Iraq, but I think they're wrong," that's fine. It's the equivalent of saying, "Jews don't believe Jesus is the messiah, but I do." It's a factually true description of their beliefs followed by your own opinion on that belief. Nothing wrong with that. But if you're saying "Democrats want to kill babies" or "Republicans want to kill Arabs," that's the equivalent of saying "Jews drink the blood of Christian children." It's offensive, stupid, and patently false. And of course, saying "Democrats are evil" or "Republicans are evil" is the exact equivalent of saying "Jews are evil."
There's a natural human tendency to demonize people who disagree with us. It's a lot easier than thinking about what they say, and trying to figure out why a decent and rational person would reach different conclusions than you. But this attitude is inherently self-destructive. If you're intentionally closed-minded, you'll never learn, grow, or even think. Worse, seeing large swaths of people as sub-human is corrupting to your own psyche. You'll inevitably end up bitter, hate-filled, condescending, and unpleasant. That's not a particularly happy way to live your life.
This tendency to demonize is latent in all people, regardless of political orientation. It's not exclusive to the left or the right. We could debate which side acts on this tendency more often, but that's missing the point. It's bad when liberals are prejudiced against conservatives, and it's equally bad when conservatives are prejudiced against liberals.
Certainly there are some political positions that are so odious and vile that a decent person wouldn't want to associate with someone who held them. Say, if someone wanted to kill all members of a certain race. Just as there are certain religious beliefs that are so odious and vile that a decent person wouldn't want to associate with someone who held them, such as believing that God wants them to kill all the unbelievers.
But if you assign this status to positions held by roughly half the country, the problem is with you, not with them. Instead of dismissing half the country, or half of humanity, as evil idiotic drooling troglodytes, you'd be better served to try to understand why they believe what they do. Don't allow yourself the intellectually lazy and dishonest dodge of assuming their beliefs are due to stupidity or evilness, but instead treat them as decent and rational. In other words, recognize that they are humans. You may still disagree with their beliefs, and there's nothing wrong with that. But at least you'll understand them. And who knows? If you're open minded enough, you may even grow and learn something.
I have a lot of friends who possess a wide variety of divergent political opinions. And because my own political beliefs are highly unconventional and eclectic, I vehemently disagree with each of my friends on at least some political issues. (And often we disagree about most issues.) But these are all wonderful people, who add significant value to my life. In conversations, we can either politely discuss politics as two rational and decent adults, or we can ignore politics and focus on the multitude of things we have in common. Either way, my friends make my life better, and I make my friends' lives better.
But if you're dismissing, discriminating against, and insulting people for political beliefs that are wholly irrelevant to how they live their lives and interact with you, you miss out on all those wonderful friendships. Instead, you get bitterness, hate, and anger. It's your life that ends up that much poorer.
To those of you planning to respond, please don't justify your hate-fueled prejudice with more hate-fueled prejudice. Don't say that you hate the other side because they're full of hate. Don't proclaim that anyone who disagrees with you is against diversity. If you're planning to do any of those things, re-read what I wrote and think about how it applies to you. It's easy to recognize that prejudice is bad when you're the one being discriminated against. The real challenge is to understand the same is true when you're doing the discriminating.