What authority does the Senate hold in the event of a presidential tie according to the 12th Amendment?

The 12th Amendment outlines the procedures for electing the President and Vice President of the United States. In the event of an electoral tie, the Senate has the authority to select the president from the top three candidates who received electoral votes. This process ensures that the Senate plays a crucial role in resolving any disputes arising from an evenly split election.

The Senate's selection of the president is a safeguard against potential deadlock that could arise from an electoral tie, thereby maintaining the stability of the executive branch. This function is specifically designed to ensure that a president is appointed even in cases where no candidate has achieved a clear majority of electoral votes.

The other options do not accurately reflect the role designated to the Senate by the 12th Amendment. For instance, deciding the outcome of a national election encompasses more than just selecting the president and is a broader function. Nominating a new president is not within the scope of the Senate's responsibilities in a tie situation, as this process is already defined by the electoral voting system. Lastly, calling for a re-election does not pertain to the authority given to the Senate under the amendment. Instead, it entrusts the Senate with the decisive role of selecting from the candidates, thereby ensuring the continuity of leadership.