Who was the Senate Majority Leader?

The Senate Majority Leader is a pivotal role within the United States Senate, responsible for coordinating and managing the legislative agenda of the majority party. Harry Reid served as the Senate Majority Leader from 2007 to 2015. During his tenure, he played a crucial role in various legislative initiatives, including the Affordable Care Act, and was instrumental in shaping Democratic Party policies during a significant portion of President Obama's administration.

Mitch McConnell, though a prominent figure in the Senate, became Majority Leader after Reid, starting in 2015. Jon Kyl and Daniel Inouye also held significant leadership positions in the Senate but did not serve as Majority Leader during the same timeframe as Reid. Thus, Harry Reid’s leadership and the impactful decisions he made during his time in office make him the correct choice for this question.