Representative Yamashita has served the residents of House District 12 [Pukalani, Makawao, Olinda, Pulehu, Kula, Ulupalakua] since his election in 2004. Recently, Sprecklesville has been added to House District 12 in the 2012 Reapportionment.

During his time in office, Hawaii faced its most serious economic crisis in recent history. As a senior member of the House Finance Committee, Representative Yamashita was able to assist in crafting a balanced State budget without raising the general excise tax, and more important for Maui residents, without taking away Maui's portion of the state hotel room tax. He continues to be committed to economic growth, especially by balancing the needs of business and labor.