n This paper discusses the relationship between interest groups and political parties and how interest groups influence the President and Congress. According to Cohen (2002, p.34) “an interest group is a private organization of individuals who have banded together because of a common cause or role”. When people join these groups, they exercise their right guaranteed by the First Amendment to the U.S Constitution to “assemble” and “petition” the government (Cohen, 2002). Interest groups can be defined according to the type of interests they defend. Examples include economic groups, spiritual groups, artistic or recreational organizations, ethnic groups, associations of local governments, and public interest groups (Cohen, 2002). Economic groups may include manufacturers, associations or labor unions. These represent the most common type of interest groups and also, in general, the type with the most resources. Within this large category, there are many more specialized groups representing specific types of industries and occupations. An example of this group would be banking and financial organizations. Examples of the latter would be professional associations. In Texas, some of these interest groups include Texas Bankers Association and Texas Medical Association (Newell et al., 2008).