The president exercises a check over Congress through his power to veto bills, but Congress may override any veto (excluding the so-called "pocket veto") by a two-thirds majority in each house. When the two houses of Congress cannot agree on a date for adjournment, the president may settle the dispute. Either house or both houses may be called into emergency session by the president. <answer>The Vice President</answer> serves as president of the Senate, but he may only vote to break a tie.
Who serves as president of the Senate?
The Vice President