Complex sentence: The Australian Democrats, formerly Australia's third party, strongly supported a move towards a republic through a system of an elected Head of State through popular voting, but the party was deregistered in 2015 due to a decline in membership.
Split into simpler sentences: The Australian Democrats, formerly Australia's third party, strongly supported a move towards a republic through a system of an elected Head of State through popular voting. However, the party was deregistered in 2015 due to a decline in membership.