Complex sentence: The leader of the federal wing of the NDP is Thomas Mulcair, who was elected in the 2012 leadership election, led the party through the 2015 federal election and then lost a party leadership review on April 10,2016.
Split into simpler sentences: The leader of the federal wing of the NDP is Thomas Mulcair, who was elected in the 2012 leadership election. He led the party through the 2015 federal election, and then lost a party leadership review on April 10,2016.