To lose one Greens Senator because he had dual citizenship was unfortunate.
To lose a second within a week because another Senator just realised that she also had dual citizenship is totally irresponsible.
Obviously the Australian Greens don't check and vet their candidates; at least not very well.
Had they checked prior to the last election, then both of these Senators could have quickly dropped their foreign citizenship.
The unfortunate aspect is that these 2 Senators were the Greens top performers. Most people actually liked and respected them. They had charm and appeal.
I'm guessing that they will attempt a comeback at the next opportunity.
Meanwhile, a couple of mediocre Greens will be promoted within the party to fill the void. Promoted through necessity and not by merit. This will probably result in a lower voter support at the next election.