The Senate has been described as a:

and even been compared to the aliens in the bar scene of Star Wars.

It boils down to Australia's bicameral system.

A bicameral system is one that has two houses or chambers.

Having two houses of Parliament means that one chamber doesn't get too big for its boots.

In Australia we have the Senate and the House of Representatives,

named after our mates over there in the USA.

The House of Representatives — or Lower House — is the house of government.

That means that the party or formal coalition with the most seats there becomes the ruling party.

If a party or coalition gets 76 or more seats out of that 150 after an election,

they get to form government.

If they've got the numbers, they can call the shots.

The House is where most legislation, called bills, originates before becoming law.

Bills have to go through both houses of Parliament before they become law.

The Senate was intended to be a house of review, that is to keep a Government

that usually has power in the House of Reps in check.

Members of the House of Reps represent a geographic area —

also known as electorates, or seats —

made up of roughly 100,000 voters each.

The electorates match up with our population spread.

So New South Wales has 47 seats, while the Northern Territory has just two.

At the moment there are 150 members of the House of Reps,

but that's going to increase by one seat in the 2019 federal election.

That's to reflect an increase in Australia's population overall.

South Australia will lose a seat — due to it's shrinking population —

while both Victoria and the ACT will each gain a seat.

The Senate, or Upper House, represents the states or territories.

So if you're a New South Wales voter, you're voting for the same candidates

whether you live in Byron or Batemans Bay.

Unlike the House, the number of Senators are spread equally across the states,

regardless of their populations.

12 each in the states, and two each in the territories,

taking us up to 76 in total.

Which gives the less populated states an edge.

Because to be elected a senator, you need roughly 14 per cent of the vote.

14 per cent of Tassie voters is a damn sight smaller than 14 per cent of Victoria's.

So that brings us back to this:

You've probably noticed that there are A LOT of independents and minor parties —

that is, not the big two — in the Senate.

They're called the crossbench because they physically sit in between

the Government and the Opposition in the chamber.

And they have a tendency to really annoy the Government.

The ruling party does not need a majority in the Senate.

In fact, that's only happened twice in the last 40 years.

The last time a ruling party also had a majority in the Senate was way back in 2004.

Having a majority in the Senate means the ruling party can get through controversial

legislation without amendment, and often with very little debate.

Which would explain some of Paul Keating's vitriol.

You're probably wondering why there are so many independents and smaller parties elected

to the Senate.

It's got to do with how we vote in the Senate, a system called proportional representation.

We'll delve into the murky world of preferences at a later date,

but let's just for now that they're super important in determining the make-up of the Senate.

Under proportional representation, when a candidate hits the required quota to get

them elected, all subsequent votes go to either whoever the candidate has preferenced,

or who you as a voter has marked as your second-in-line.

That redistribution keeps on going until other candidates hit their limit for the quota.

Independents and smaller parties, who may not have the star power to hit a quota on their own,

are usually elected on preferences of voters who gave their first vote to another candidate.

Which is why people who only get a handful of primary votes, can end up as elected Senators.

Voters can vote above the line, which means they pick their favourite party and let the

party order the candidates how they please.

Or they can vote below the line, where they can choose whatever candidates

in whatever order they like.

Just before the 2016 federal election, then-prime minister Malcolm Turnbull changed the

rules for how we vote in the Senate.

Before then, you either had to vote for one above the line,

or number each and every single box below the line.

In a state like New South Wales, there were literally dozens of candidates.

So it's no surprise that only 4 per cent of voters chose that option.

From 2016 onwards, voters will have to number at least 6 boxes above the line, or 12 below.

The idea was that it would give voters more control over where their votes go.

But in practice, it also reduced the iron-clad grip that major parties had on candidates.

Both Labor's Lisa Singh and Liberal candidate Richard Colbeck won spots in the Senate

from seemingly unwinnable positions on the ballot, by mounting a grassroots campaign

to get their supporters to vote below the line.

That's how you vote for the Senate.

The number of candidates per seat is substantially less

than the number of candidates on the Senate ballot.

Voters have to rank every candidate in order of preference.

So that cuts out those opaque backroom deals made between parties

that can sometimes happen in the Senate.

Political parties will try to influence your preferences with how-to-vote cards,

but really the ultimate power when it comes to voting for a House of Reps candidate

lies with you, the voter.