[1] Ho served on the third National Assembly as a member of the Democratic Progressive Party,[2][3] but switched affiliations to represent the newly founded Taiwan Solidarity Union in the 2001 legislative elections.

[4][5] During his first term, Ho was a member of the Legislative Yuan's National Defense Committee.

[6][7] Near the start of his second term, the Taiwan Solidarity Union named Ho one of its caucus whips.

[10] Incumbent Taichung mayor Jason Hu retained his office, and Ho was later named a member of the Taiwan Solidarity Union's Central Executive Committee.

[11] Ho rejoined the Democratic Progressive Party in November 2007, after defeating Wang Shih-hsun in a public opinion poll used to determine the Pan-Green Coalition's legislative candidate,[12] and lost his legislative seat to Daniel Huang.