[1] Given the two-party nature of the U.S. system, the minority leader is almost inevitably either a Republican or a Democrat.
The position could be considered similar to that of the leader of the opposition in parliamentary systems.
Contrastingly, in upper houses, the titular speaker is frequently a separately elected officer such as a lieutenant governor or vice president.
Some votes are deemed to be so crucial as to lead to punitive measures (such as demotion from choice committee assignments) for members who violate the party line; decisions such as these are often made by the minority leader in conjunction with other senior party leaders.
At times, particularly during crucial legislation, the minority leader may be consulted by the opposite leader in order to more easily get things passed and ensure that provisions important to the interests the minority party be included.