Comment: Yes

Rand Paul, and other senators there helping support his cause, are trying to pressure the Executive Branch (President Obama) to give a clear answer on their view of whether they have power to conduct targeted drone strikes on a U.S. citizen on U.S. soil without due process as guaranteed by the Constitution. In other words, can they kill Americans without due process, but instead under their own opinion of their own power.

No branch of government - Congress, Supreme Court, Executive - has absolute authority over the other. So neither Senator Rand Paul or Congress can force the president to answer. All he/they can try and do is pressure him to answer by getting public opinion on the issue on their side. This unusual tactic, the filibuster, gets news attention and therefore the attention of the American public the longer it goes on.