Kao was elected to the
Legislative Yuan in 2004 after having served on the
Taipei City Council. In 2007, he was involved repeated altercations with
Kuomintang legislator
Chu Fong-chi. In May, the
Kuomintang accused Kao of slander for his comments on the
party's assets. Kao and
Yu Jane-daw filed a separate lawsuit against former Taipei mayor
Ma Ying-jeou for allowing a private organization to use public land for profit. Kao was an early supporter of
Frank Hsieh's 2008 presidential campaign. Hsieh was eventually named the
Democratic Progressive Party's nominee, but lost the office to KMT candidate Ma Ying-jeou. Kao's own legislative reelection campaign was opposed by a coalition of
LGBT rights activists, and he lost to KMT opponent
Ting Shou-chung. Later, Kao served as the Democratic Progressive Party's deputy secretary-general. He lent support to the independent presidential campaign of activist , but she dropped out in September 2011, before the registration deadline for the 2012 election. Kao was named a DPP legislative candidate for
New Taipei's 11th district in the same election cycle, but was again defeated, this time by
Lo Ming-tsai. Kao returned to the government in 2018, as the deputy minister of the
Overseas Community Affairs Council. ==References==