One possibility is the amount of detail that government classes entail. You are talking about plenty of names for Bills, Laws, and Amendments. Along with this, there are a lot of names involved, years, and numbers. Our government system is not entirely easy to comprehend, since is a tri-partite system, and each has a set of his own rules and regulations to follow.
We also have to deal with timelines, comparisons to other government systems, the historical context within which the government has changed through time, and the complex nature of the duties and responsibilities of each task at hand and the way that government officials are voted in.
There is really a lot of information which STILL people confuse to this day even as they are told over and over the same information. Remember, there are STILL people that do not even know who was our last Vice President.
I agree with the previous post in that some clarification is needed. To a certain extent, I can understand that if one is being introduced to the concepts explained in government classes, it can seem like the same elements are repeated multiple times. Yet, I would counter with two points here. The first would be that different aspects of the same topic can be revealed, making it an entirely different experience. For example, you could make the argument that government classes may address the same topic in different ways. This is not an example of talking about "the same thing over and over," as a new venue of exploration is revealed. Another point I could make is that over time, one develops a sense of understanding the intricate nuances within government, so that with greater exposure, the concepts are not repeated as much as refined with more detail and precision.
Is it possible that your teacher does not think the class understands the material presented? Sometimes my students have that blank look on their faces that tells me they have not heard what I have said or have not understood what I have said. When students actively participate in class discussion, I know that they do understand, or that they are at least interested in understanding. Most teachers today do not even lecture at all, much less go over the same material over and over again. We know that it is up to the students to be active participants in their own learning. It is our job to just facilitate that learning. If you have a good grasp of government and civics, what you might want to do is ask your teacher to give you an extra credit assignment so you can learn more or dig more deeply into this subject. One important purpose of education is to help you prepare to be a participating citizen in our democracy, so the more you know, the better off all of us will be!
It is really hard to answer this question without knowing what is going on in your own class. What do you think is being said over and over?
I have taught government classes in high school and in college and I do not think I say the same things over and over. There will be some themes that you should be talking about often. For example, I often use the theme of democracy and look at how democratic various parts of our political system are. So in that case, you'd be hearing about democracy over and over because it's the major theme of the class.
Anyway, if you can be more specific, I might be able to explain why it's happening, otherwise, I'm not sure.