Why did the Association of Southeast Asian Nations (ASEAN) establish its first regional human rights mechanism, the ASEAN Intergovernmental Commission on Human Rights (AICHR), and in what ways did non-state actors, such as regional civil society actors, affect the state-centric ASEAN decision-making for the AICHR's establishment?<br>To provide answers to these questions, it is imperative to grasp the complex interactions among regional track 2, think-tank- and university-based networks, regional track 3 human rights non-governmental organizations and civil society actors vis-à-vis track 1 ASEAN body.<br>This study illuminates the networking cooperation among track 2 and 3 actors within the context of the multi-track style of human rights governance in ASEAN. The concept of “horizontal dialogue” among them is employed in this study to help us understand this networking style of politics. This horizontal networking encapsulated the social life of these actors: they simultaneously engage with contention and deliberation to achieve their objectives of making ASEAN “people-oriented” at the time when ASEAN began drafting the ASEAN Charter in 2006 and writing the Terms of Reference (TOR) for subsequent regional human rights mechanisms in 2008.<br>This paper empirically traces and compares the two most influential track 3 civil society actors in the horizontal networking politics against the background of these historical junctures for ASEAN. The Working Group for an ASEAN Human Rights Mechanism (WGAHRM), based in Manila, was established in 1995 to materialize ASEAN's consideration of establishing a regional human rights mechanism. The Solidarity for Asian People's Advocacy (SAPA), a loose coalition of center-leftist ideological NGOs and civil society actors, was formed in 2006, the same year that ASEAN nominated the Eminent Persons Group for creating a Charter. The WGAHRM pursued “public-private partnership” in its advocacy strategy, to graft the 2004 Vientiane Action Programme onto a regional human rights mechanism that ASEAN seemed to lack both willingness and expertise to create. In contrast, in pursuing its more ambitious objectives, the SAPA mobilized what might be termed as a “counter-power initiative” toward ASEAN. Both actors capitalized on the track 2 venues created by the ASEAN-Institute of International Studies since 1990s onwards, directly talked with ASEAN officials, and hosted a series of workshops and conferences to articulate their advocacies.<br>This paper demonstrates that the WGAHRM's PPP advocacy functioned better, but at the same time, it posits a third type of advocacy—the ASEANstyle “Trojan Horse” that brought core key persons from regional civil society organizations to advance the AICHR's human rights promotion agendas. Yet in a formative phase, the composition of the AICHR may hold a key to filling a void in the TOR of the AICHR—the human rights protection activities- by linking the body with like-minded regional civil society actors.