<P> The Constitution also provides for appointment of one of the elected senators to serve as President pro tempore . This senator presides when the vice president is absent from the body . The president pro tempore is selected by the body specifically for the role of presiding in the absence of ( as the meaning of pro tempore , literally `` for the time being '' ) the actual presiding officer . By tradition , the title of President pro tempore has come to be given more - or-less automatically to the most senior senator of the majority party . In actual practice in the modern Senate , the president pro tempore also does not often serve in the role ( though it is their constitutional right to do so ) . Instead , as governed by Rule I , they frequently designate a junior senator to perform the function . </P>
who serves as president of the senate in his absence
appointment of one of the elected senators to serve as President pro tempore