Ok, this may sound like a complaint, and I'm terribly sorry if it does, but there is one major misconception that drives me insane. My history teacher this morning decides he's going to try to teach the class about what it means to be a "Democrat" and what it means to be a "Republican". Now, his basic definition that good majority of Democrats are liberal is correct, and that a good majority of Republicans are conservative, but he doesn't bother defining the difference between liberalism and conservatism. Thus, his lesson gave off the aura that Democrat = liberal and that Republican = conservative. As that may be the situation in present day America, that is just not politically correct (no pun intended). To be a Democrat, for the sake of simplicity, means to believe in large government, and to be a Republican means to believe in small government. But these are not the defining factors of what liberal and conservative mean.
Liberalism is the idealism that is new or revolutionary for the day. A liberal person believes in ideals that are not widely accepted (i.e. gay marriage, immigrant rights, universal health care, pro-choice, higher taxes, etc.) and that personal liberty is most important. Conservatism is the idealism that is "old" or widley accepted by the majority of the public (i.e. pro-life, smaller taxes, anti-gay rights, restricted immigrant rights, etc.) and they believe tradition is most important. This means that the role of a political party changes depending on the stand they take on social and economic issues. Today Democrats are stereotypically liberal and Republicans are stereotypically conservative. However, back in the 1860's, the Republicans were the liberal party and Democrats were the conservative party. The only thing that consistantly defines a Democrat or Republican is their view on the proper role of government.
In fact, this is the only factor that has stayed consistant throughout America's history. Politicians have been arguing about the role of government since the conception of The Constitution - federalists wanted a larger government, and anti-federalists wanted a smaller government. To some extent, these are now the parties that exist today, except under different names. Keep in mind that I'm leaving out a lot of history for simplicity's sake, but it's undeniable that this central arguement has been pivital within the past 221 years.
Otherwise, I think teachers need to make a point to explain to their students that Democratic-conservatives and Republican-liberals DO exist. You can believe that government should have a bigger role in people's lives but that a woman should not abort their children. You can believe that government should play a smaller role in America and believe that gays should have every right to marry. There is a difference between a political party and a political philosophy. The problem is Americans today seem to mesh the two ideas as if they're the same thing.
Now, that's not to say that I wasn't one of these Americans myself. I was extraordinarilly naive to this difference until just a while ago. But, the fact that I didn't understand this essential difference scares me, especially since I know I'm not the only one. We're living in this country and yet we don't understand the basic principles of how our politics work. Scarier still is that teachers don't even adress this issue. They leave students to believe stereotypes they take as truth, some even reinforce it.