<P> Seniority in the United States Senate is valuable as it confers a number of benefits and is based on length of continuous service, with ties broken by a series of factors . Customarily, the terms "senior senator" and "junior senator" are used to distinguish the two senators representing a particular state . </P> <P> The United States Constitution does not mandate differences in rights or power, but Senate rules give more power to senators with more seniority . Generally, senior senators will have more power, especially within their own caucuses . In addition, by custom, senior senators from the president's party control federal patronage appointments in their states . </P> <P> The president pro tempore of the Senate is traditionally the most senior member of the majority party . </P> <P> There are several benefits, including the following: </P>

Majority party member with the most seniority is called