Have crunched some numbers on the Senate now and it is an interesting outcome. A lot of us will be lamenting that the UAP somehow managed to get the last seat in Victoria, but when you look at all of the votes and the proportion of seats won on a national scale it isn't so bad.
Here's what I found:
Clearly the biggest outlier is David Pocock with 0.4% of the primary vote and 2.5% of the seats won. That said, he won in a territory which is much harder as there are only 2 seats on offer.
The major party combined vote is, predictably, lower than for the House, only 64.33%.
Also worth noting is that the combined primary vote of all the parties and the independent who won a seat adds up to 85.35% of the votes, so there are 15% of votes which went to losing candidates but likely contributed via preferences to others getting elected.
Even more striking is that the major parties were below 60% in both Tasmania and the ACT, which explains how both those electorates ended up electing candidates specific to them (Jackie Lambie Network in Tassie and David Pocock in ACT).
Pocock and Lambie only ran in one electorate each, so their share of the national vote is minimal.
One factor in the election of the UAP candidate in Victoria was exhausted votes. An exhausted vote cannot happen in the House as preferencing all the way down the ballot paper is compulsory. In the Senate you can vote for as few as 6 tickets, and your vote may go nowhere if you don't preference far enough down the ballot paper. In effect, this is a wasted vote as all of your preferred candidates were excluded before the last 2 candidates were competing for the last (6th in states) seat. In Victoria there were 261,000 exhausted votes, the last 2 candidates were a LNP candidate and a UAP candidate. The UAP candidate won by around 75,000 votes. This is why I said to preference as far as the LNP if you prefer to have an LNP Senator as opposed to who knows what we will get with the UAP Senator. Still, if you look at the country as a whole the UAP got just under 3.5% of the vote and 2.5% of the seats on offer . . . but did it have to be Victoria?
Of course, each state gets the same number of Senators, as a result a quota (votes needed to get elected) was 685,000 in NSW as opposed to 51,000 in Tasmania. Even though the Territories only get 2 Senators each the quota in NT was 31,000 (but a higher proportion of the vote as you need one third + 1 votes as opposed to one seventh + 1 votes in a state).
The Senate is complicated but what we have ended up with is:
One Nation: 2
Remember, of the 74 Senators, 35 were elected in 2019 (half of the Senators for each state, but not for the Territories).
So, to pass a bill you need 37 votes as the President (equivalent to the Speaker of the House) only gets a casting vote. Assuming the ALP provides the President they can pass a bill with the Greens support and don't need anyone else.