Prior to contesting the legislative elections of 2001, Lu served three terms on the Hualien County Council.[3] His victory over Michael You in the legislative primaries held that April was considered unexpected,[4][5] and subsequently he was elected to represent the Hualien County district in December.[6] Shortly after taking office in February 2002, Lu received a single vote in a speakership election won by Wang Jin-pyng.[7] The next year, Lu led You's campaign as he contested the Hualien County magistracy.[8][9] As leader of the Democratic Progressive Party's campaign headquarters, Lu coordinated party efforts on behalf of its 2004 presidential ticket.[10] During Lu's first term, he supported the establishment of direct flights between Hualien Airport and Seoul.[11] In November 2004, Lu proposed that freeing captured animals be prohibited, to prevent commercialization of the release.[12]
Lu was again named a DPP legislative candidate in 2004,[13][14] and was reelected alongside Fu Kun-chi.[15][16] Lu backed the construction of a freeway between Hualien and Yilan during his second term in office.[16][17] The DPP nominated Lu as its candidate for the Hualien County magisterial election in 2005.[18] He lost the contest to Hsieh Shen-shan. Lu ran for legislative reelection in 2008,[19] losing to Fu Kun-chi.[20]