Complex sentence: Henare's own involvement with Māori politics first came with Mana Motuhake, a purely Māori party, but when Winston Peters (himself half Māori) established the New Zealand First party, Henare changed the focus of his activities.
Split into simpler sentences: Henare's own involvement with Māori politics began with Mana Motuhake, a purely Māori party. When Winston Peters (himself half Māori) established the New Zealand First party, Henare changed the focus of his activities.