There are many ways that our ideas are shaped and influenced as we grow up. This process by which we develop certain ways of thinking is called political socialization. There are three main influences which change and shape us being, the family, the mass media, and formal education.
The family definitely has the greatest impact on us as we grow. This is primarily because ever since the beginning of childhood we are exposed to the ideas of our parents. Their ideas are the ideas that young children learn, and soon begin to form these ideas are their own. The saying that "You never get a second chance to make a first impression" holds true here in that this is what first the child is exposed to, and it is hard to get people to change from their original ideas of politics, or anything for that matter. In 1965 Jennings and Niemi selected a sample of high school seniors throughout the country and found that 58.9% of them had chosen the same party as their parents.
Another influence on how people are shaped is the Mass Media. Today more and more people are spending more and more time watching television. The average grade school student spends more time watching tv than he or she does at school. The media has been called the "new parent" by some. However, the programs that would influence political opinion the most, such as the news, are rarely watched by the youth of today.
The final major influence of people political socialization is their formal education or school. Countries have historically had government classes in their schools to "preach" the goodness of their particular type of government. For example, American children have been taught the virtues of capitalism and democracy for years. In Germany, during the Nazi era, children were taught how murders could be justified in certain situations.
There are certain types of ways used to measure the public's opinion once they have been formed. There are usually samples that are performed instead of complete polls because it can save a lot of time. Scientific sampling is polling random people to form the general opinion of many people.
In closing, it is evident by reading above that people today are influenced by the Mass Media, schools, and probably most importantly, families.