Manuel is former Chair and Professor of Politics at Saint Anselm College, and the co-founder of the New Hampshire Institute of Politics, where he served as its Executive Director. He has also been a member of the National Screening Panel for the Graduate Fulbright Competition for the Spain and Portugal program, and was an Affiliate at the Minda de Gunzburg Center for European Studies at Harvard University, where he co-chaired the Iberian Studies Group.