The is a powerful politician who represents the majority party in the House, makes appointments, and refers legislation to committees.

The Speaker of the House.

Explanation:

In the legislative assembly, the Speaker of the House acts as the leader of house elected by the majority members of the house. As the speaker is elected by the majority, he/she is elected by the majority party on their behalf.The speaker is the presiding officer who takes in-charge of the whole legislative assembly process. He/she  is a powerful politician who represents the majority party in the House, makes appointments, and refers legislation to committees.