Complex sentence: One of these was Winston Peters's New Zealand First party, a radical centrist and nationalist party opposed to immigration-strong campaigning by Peters allowed the party to return from its serious losses in the 1999 election.
Split into simpler sentences: One of these was Winston Peters's New Zealand First party, a radical centrist and nationalist party opposed to immigration. Strong campaigning by Peters allowed the party to recover from its serious losses in the 1999 election.