Australian Senate

The Senate is the upper house of the bicameral Parliament of Australia, the lower house being the House of Representatives. The composition and powers of the Senate are established in Chapter I of the Constitution of Australia. There are a total of 76 Senators: 12 are elected from each of the six Australian states regardless of population and 2 from each of the two autonomous internal Australian territories (the Australian Capital Territory and the Northern Territory). Senators are popularly elected under the single transferable vote system of proportional representation.

Unlike upper houses in other Westminster-style parliamentary systems, the Senate is vested with significant powers, including the capacity to reject all bills, including budget and appropriation bills, initiated by the government in the House of Representatives, making it a distinctive hybrid of British Westminster bicameralism and United States-style bicameralism. As a result of proportional representation, the chamber features a multitude of parties vying for power. The governing party or coalition, which has to maintain the confidence of the lower house, has not held a majority in the Senate since 2005-2007 (and before that since 1981) and usually needs to negotiate with other parties and independents to get legislation passed.

Origins and role
The Commonwealth of Australia Constitution Act (Imp.) of 1900 established the Senate as part of the system of dominion government in newly federated Australia. From a comparative governmental perspective, the Australian Senate exhibits distinctive characteristics. Unlike upper Houses in other Westminster system governments, the Senate is not a vestigial body with limited legislative power. Rather it was intended to play – and does play – an active role in legislation. Rather than being modeled solely after the House of Lords, as the Senate of Canada was, the Australian Senate was in part modeled after the United States Senate, by giving equal representation to each state and equal powers with the lower house. The Constitution intended to give less populous states added voice in a Federal legislature, while also providing for the revising role of an upper house in the Westminster system.

Although the Prime Minister of Australia and Treasurer of Australia, by convention, are members of the House of Representatives (after John Gorton was appointed prime minister in 1968, he resigned from the Senate and was elected to the House), other members of the Cabinet of Australia may come from either house,[3] and the two Houses have almost equal legislative power.[2] As with most upper chambers in bicameral parliaments, the Senate cannot introduce or amend appropriation bills (bills that authorise government expenditure of public revenue) or bills that impose taxation, that role being reserved for the lower house; it can only approve, reject or defer them. That degree of equality between the Senate and House of Representatives reflects the desire of the Constitution's authors to address smaller states' desire for strong powers for the Senate as a way of ensuring that the interests of more populous states as represented in the House of Representatives did not totally dominate the government. This situation was also partly due to the age of the Australian constitution it was enacted before the confrontation in 1909 in Britain between the House of Commons of the United Kingdom and the House of Lords, which ultimately resulted in the restrictions placed on the powers of the House of Lords by the Parliament Acts 1911 and 1949.

Electoral system
The system for electing senators has changed several times since Federation. The original arrangement involved a first-past-the-post and block voting or "winner takes all" system, on a state-by-state basis. This was replaced in 1919 by preferential block voting. Block voting tended to produce landslide majorities and even "wipe-outs". For instance, from 1920 to 1923 the Nationalist Party held all but one of the 36 seats, and from 1947 to 1950, the Australian Labor Party held all but three.
In 1948, single transferable vote with proportional representation on a state-by-state basis became the method for electing Senators. This had the effect of limiting the government's ability to control the chamber, and has helped the rise of Australian minor parties.

From the 1984 election onwards, group ticket voting was introduced, in order to reduce a high rate of informal voting that arose from the requirement that each candidate be given a preference, and to allow small parties and independent candidates a reasonable chance of winning a seat. This allowed voters to select a single party "Above the Line" to distribute their preferences on their behalf, but voters were still able to vote directly for individual candidates and distribute their own preferences if they wished "Below the Line" by numbering every box.

In 2016, group tickets were abolished to avoid undue influence of preference deals amongst parties that were seen as distorting election results[6] and a form of optional preferential voting was introduced. As a result of the changes, voters may assign their preferences for parties above the line (numbering as many boxes as they wish), or individual candidates below the line, and are not required to fill all of the boxes. Both above and below the line voting now use optional preferential voting. For above the line, voters are instructed to number at least their first six preferences; however, a "savings provision" is in place to ensure that ballots will still be counted if less than six are given. For below the line, voters are required to number at least their first 12 preferences. Voters are free to continue numbering as many preferences as they like beyond the minimum number specified. Another savings provision allows ballot papers with at least 6 below the line preferences to be formal. The voting changes make it more difficult for new small parties and independent candidates to be elected to the Senate, but also allow a voter to voluntarily "exhaust" preferences — that is, to ensure their vote cannot flow to specific candidates or Parties — in the event that none of the voter's candidates preferences are elected.

Membership
Under sections 7 and 8 of the Australian Constitution:
The Senate must comprise an equal number of senators from each original state,
each original state shall have at least six senators, and
the Senate must be elected in a way that is not discriminatory among the states.
These conditions have periodically been the source of debate, and within these conditions, the composition and rules of the Senate have varied significantly since federation.