You lost me a little here, but I'm not fully across the impact of Senate terms and a DD. From what Cormann was saying it seems that people will vote 1-6 ATL or 1-12 BTL. If there remains a desire for people to vote non-major party in the Senate and that trend continues generally I guess the impact of the new rules is a bunch of people will have a vote that never gets counted because the micro-party they've chosen won't ever channel enough preferences to one group because it stops at 6? And presumably the deal-making that goes on will see the majors working hard to get themselves in the top 6 of the major micro parties (a Stephen Mayne type or something) so that they might make an extra quota, but then they'll have little to bargain with as their preferences stop at 6 too...?
It's all a bit confusing to me. I still feel the way the Senate played out this election was nowhere near as bad as feared and so the impetus for change doesn't appear to be there. It's just the Libs taking advantage of Ricky Muir's surprise elevation and the apparent confusion caused by the Liberal Democrat Party (Leyonhjelm) being 1st on the NSW Senate ballot.
In a DD, half of the Senators elected for the states are only elected for three years. These are the Senators elected from 7-12.
Let's use South Australia as an example, with first preference votes as follows:
Lib: 28
NXT: 26
ALP: 24
Grn: 10.5
Oth: 11.5
The order of election will be this, with the remaining votes in brackets
1. Liberal (20.3)
2. Xenophon (18.3)
3. Labor (16.3)
4. Liberal (12.6)
5. Xenophon (10.6)
6. Labor (8.6)
7. Liberal (4.9)
8. Xenophon (2.9)
9. Greens (2.8)
10. Labor (0.9)
11. Liberal/minor party
12. Xenophon/Greens/minor party
So, the six elected for a full term will be 2 Lib, 2 Xen and 2 Lab, while the six elected for a half term will be 1/1/1/1 and two unknowns.
Now, imagine this in other states. With no Xenophon to take a massive share of the vote (although his party could nab a Senate seat somewhere else, just not on first pref), the first six are likely to be 3 from the Coalition, 2 from Labor and 1 from the Greens or 3 and 3 for the majors.
Let's say the Christian Democrats and Shooters and Fishers take advantage of their larger minor party vote share in NSW and get the last two Senate seats (unlikely, but for the sake of the exercise let's assume it). They would be elected at 11 and 12. The NSW election would look something like:
1. Liberal
2. Labor
3. National
4. Labor
5. Liberal
6. Labor
7. Liberal
8. Labor
9. Greens
10. National
11. Christian Democrats
12. Shooters & Fishers
So, at the 2019 half-Senate election, the seats up for grabs would be 2 Coalition, 1 Labor, 1 Greens, 1 CDP, 1 S&F, and the replacements will probably be 3 Coalition, 2 Labor, 1 Greens. Copy this across the board, and the crossbench goes from 18 to about 8.