Political Socialization is affected by

Political socialization is the process through which a person develops political beliefs and opinions that influence their behavior in social spheres.

Factors that affects the political socialization, are the things that influence your political ideas or values. They're typically listed as::

family,

media,

peers,

education,

religion,

faith,

race,

gender,

age and

geography.

Each of these has an influence, or at least a correlation to, certain political parties, values, and ideologies. 

The importance of each of these may change throughout your lifetime. As a child, your family has the greatest influence over your political and party preferences.

Then as you age, your peers and educaction will begin to influence you even more so.

The party you claim by young adulthood will likely stay with you through life, although your ideologies may shift over time (such as how individuals tend to become more conservative as they age).

Obviously this is far from conclusive and there are exceptions to every rule, but in general, these hold to be true.