Political t-shirts are a great way to make a statement to the world, while showing your support to a certain party, whatever party that is. With political t-shirts, you can make almost any statement you want about your party. They are an easy way to relay a message and a stylish way to get people's attention on certain issues. People tend to wear political t-shirts around election time, but they can also be worn at other times as well.
Conservative t-shirts generally have a message about change, about an issue that is strongly supported by the party, as well as some funny GOP humor.
Conservative t-shirts are just as they sound- conservative. They do not venture into very adventurous messages or issues. In fact, their messages are fairly predictable. And since the conservatives are in office currently, there aren't very many threatening conservative t-shirts.
Liberal t-shirts, on the other hand, are a little bit more risqué since they are statements made against the party that is in house. Liberal t-shirts generally do not hold anything back and they all go against issues and policies that are country is in the midst of dealing with. In order to get liberal t-shirts, you have to be ready to make a statement about something.