The post under his name said those who were responsible for insults aimed at his daughter “must be new arrivals”. His post appeared on Facebook’s Adelaide Hills Chat site, a closed group with 16,000 members. A screenshot of Nicky Downer's Facebook post in the Adelaide Hills chat group. Ms Downer has been called “Out of Towner Downer” because she had moved away from the Adelaide Hills electorate about 20 years ago. Her conservative political views and membership of the Institute of Public Affairs have come under such sustained social media attack that she quit Twitter early in the campaign, citing “trolls” and abusive language.

Polls showed Ms Downer lagging badly behind Ms Sharkie, the candidate for Centre Alliance, throughout the long campaign. Ms Sharkie easily won Mayo, which she had to quit in the midst of the dual citizenship fiasco. Mr Downer’s intervention at 11.12pm on Friday followed a Facebook post by his wife, Nicky Downer, urging support for their daughter. In a later post, she expressed surprise and disappointment at the level of intolerance she said she had witnessed on Adelaide Hills Chat during the byelection. A screenshot of Alexander Downer's Facebook post in the Adelaide Hills chat group.

“I agree with my wife,” Mr Downer’s post to the Adelaide Hills Chat site began an hour later. “We are Adelaide Hills people and been in politics here for decades and through multiple elections never come across such abuse. “Sharkie supporters have brought horrible hate to our district. “Never seen this before. “You must all be new arrivals.”

Mr Downer’s effort was greeted by a torrent of scorn and some support from other Facebook members. “Typical Liberal – thinks we’re all boat people,” was one of the early responses. One urged the Downers to “cop it on the chin”. Another said that “wheeling out the olds to beg people to vote for their kid is a new wrinkle in political campaigning”. Loading “Pot. Kettle. Black,” chimed in another. “Don’t give it if you can’t take it, love.”

Yet another urged: “Mr and Mrs Downer it is time to cut the umbilical cord.” But another member of the chat group said she was amazed at “how much nastiness has been thrown at Georgina and her family”, and added “of course her parents are going to be supportive as any good parents would be”. Another said she had been extremely upset at the behaviour of a busload of people attending a “meet the candidates” evening “who were intent on heckling Georgina Downer for no apparent reason other than to be offensive”.