Division of North Sydney

The Division of North Sydney is an Australian electoral division in the state of New South Wales. It was proclaimed in 1900 and was one of the original 75 federation divisions contested at the first federal election.

Located along Sydney's North Shore, the division is named after the North Sydney area and includes the suburbs of Artarmon, Cammeray, Castlecrag, Crows Nest, Greenwich, Henley, Hunters Hill, Huntleys Cove, Huntleys Point, Kirribilli, Lane Cove, Lane Cove North, Lane Cove West, Lavender Bay, Linley Point, Longueville, McMahons Point, Middle Cove, Milsons Point, Naremburn, North Sydney, North Willoughby, Northbridge, Northwood, Riverview, St Leonards, Tarban, Waverton, Willoughby, Willoughby East, Wollstonecraft, and Woolwich; as well as parts of Chatswood, Chatswood West, Cremorne, Gladesville, Gore Hill, and Neutral Bay.

Second only to the nearby Division of Wentworth, the Division of North Sydney has the nation's second highest proportion (56.4%) of high income families. As with all North Shore seats, the division has usually been a comfortably safe seat for the Liberal Party of Australia and its predecessors. Labor has usually run dead in this seat, though it came within 3.1 percent of winning it at the 1943 election landslide. North Sydney and Wentworth are the only two federation divisions in New South Wales to have never been held by Labor. It has been held by a member of a non-Labor party for all but six years of its existence, when held by "father of the independents" Ted Mack, from the 1990 election before choosing to resign from federal parliament after two terms at the 1996 election, for the same reason he previously chose to resign from state parliament after two terms − to avoid receiving a parliamentary pension.

However, during Mack's tenure, North Sydney was always a safe Liberal seat in traditional two-party matchups, and it was a foregone conclusion that it would revert to the Liberals once Mack retired. As expected, when Mack retired in 1996, Joe Hockey reclaimed the seat for the Liberals and held it until 2015, serving as Treasurer from 2013 to 2015 in the Abbott Government. Following the successful September 2015 Liberal leadership spill Hockey moved to the backbench, however six days later he announced his intention to resign from parliament, taking effect from 23 October. The 2015 North Sydney by-election occurred on 5 December to elect his replacement, Trent Zimmerman, a former Hockey staffer, despite a large swing.

Zimmerman won with 48.2 percent of the primary vote after a larger-than-predicted 12.8 percent swing against the Turnbull Coalition Government. This was only the second time in North Sydney since federation that the successful Liberal candidate did not obtain a majority of the primary vote and had to rely on preferences. Zimmerman faced a double-digit primary vote swing − more than triple that of the 2015 Canning by-election − even though Labor did not even contest the seat.

The Liberal two-candidate vote of 60.2 percent against independent Stephen Ruff compares to the previous election vote of 65.9 percent against Labor. The reduction of 5.7 percent cannot be considered a "two-party/candidate preferred swing" − when a major party is absent, preference flows to both major parties does not take place, resulting in asymmetric preference flows.

Ian Macfarlane attempted to defect from the Liberal party room to the National party room with accompanying demands for additional Nationals cabinet representation, and the Mal Brough James Ashby diary controversy deepened in the last week of the campaign. Along with the unexpected by-election swing and Turnbull's significantly lessened personal ratings in the concurrent December Newspoll, some News Corp journalists opined Malcolm Turnbull's honeymoon to be over.

Zimmerman became the first openly-LGBTI member of the House of Representatives.