Australian Politicians Were Already on Edge Before One of Their Own Was Attacked Much remains unclear about why a driver ran a car into Helen Haines, a lawmaker. Even so, fellow representatives, especially women, spoke of feeling threatened in a polarized atmosphere.

Helen Haines, an independent lawmaker, was still in critical condition after being struck by a vehicle in what the police called a “targeted” attack, when the comments appeared on fellow female politicians’ social media pages.

“What a shame you weren’t there,” one person wrote on the page of Georgie Purcell, a state legislator whose district overlaps with Ms. Haines’s electorate. “She deserves to meet a Land Cruiser,” another wrote in response to an unrelated post by Tanya Plibersek, the minister of social services, in a specific reference to the model of the car that drove into Ms. Haines.

Much remains unknown on Wednesday about the incident two days earlier that shocked the country, when a driver plowed into Ms. Haines outside her electoral office in Wangaratta, in a rural corner of the state of Victoria, leaving her with serious injuries.

Even so, politicians across the ideological spectrum, law enforcement and commentators said it seemed inevitable in the increasingly polarized climate, in which charged language and tirades bordering on threats had become the norm.

A 43-year-old man from Ms. Haines’s district, Brendan Nugent, appeared in court on Wednesday, facing charges of dangerous driving, causing serious injury and causing harm to a Commonwealth public official. The police said additional charges could still be brought as the investigation continued, and that they believed the incident was a “deliberate but isolated act.”Phil Haines, Ms. Haines’s husband of 40 years, said on Wednesday that surgeons had been forced to amputate both of her legs. Ms. Haines was standing behind the trunk of her own vehicle when she was struck, officials said.

“The good news in all of this is Helen is alive, and she’s stable,” Mr. Haines said of his wife, a former nurse who had welcomed new grandchildren in recent months.

“Helen’s road to recovery will be long and difficult, but she is a fighter,” he said, his voice breaking by the end. “She is a determined person who will do her best, with our support and love, to recover.”Krissy Barrett, commissioner of the Australian Federal Police, said on Wednesday that investigators were still working to determine the motive behind the attack. Nevertheless, the attack “is what many had been dreading for some time,” she said in a“Commonwealth parliamentarians have become increasingly worried about threats directed at them and at their staff,” Ms. Barrett said, adding that investigators with the federal police were charging “almost one individual every week” for targeting members of Parliament or high officeholders.

The sense of threat was further heightened on Wednesday afternoon, when the police in Western Australia, on the other side of the country, arrested a man on suspicion of making verbal threats at an electoral office in Perth while carrying what appeared to be nunchucks.

The police did not say whose office it was, but they said it was on Albany Highway in Victoria Park.

Hannah Beazley, a state representative for Victoria Park, whose office is on that street, said in a statement to local media that a member of the public had entered her office armed with a weapon, and that her staff was “shaken and upset.”There were no injuries, according to the police.

Many politicians said the new environment was threatening Australia’s cherished, down-home style of democracy, where constituents could easily approach their representatives at football matches, community events and local shops, without the throngs of security that shadow high-level officials in places like Britain or the United States.

Australian politics have seen tensions ratcheted up as a far-right party, One Nation, surged to unprecedented levels of support, disrupting a longstanding status quo of the two established parties. The fragmentation has meant increasingly no-holds-barred commentary on topics like immigration, religion and events in the Middle East, amplified by the explosive reach of social media platforms that can fuel the most extreme arguments.

Anne Aly, the minister for small business, said she had received 19 death threats on social media after another lawmaker, Angie Bell, said Ms. Aly should be “shamed and stoned in the square” for a decision over credit card payments to the tax office. Ms. Bell subsequently withdrew her statement, which she made last week during a speech in Parliament.

Ms. Plibersek, who has been in elected office since 1998, said threats had always been part of life in the public eye, but that they had increased in recent years.

“I couldn’t even count the number of death threats, rape threats that I’ve had over the years, including ones that have ended up in court,” she said in an interview with the Australian Broadcasting Corporation. “The thing that’s changed most is the industrial scale of that abuse now. And there’s always been abuse, but I am shocked by the tenor of it.”David Pocock, an independent senator, said this week that his family had to move homes because of security concerns.

“I think we do need to acknowledge that much of the anger, the division, the at times incredibly hateful comments that have festered in this age of anonymous social media accounts, has spilled over into the real world,” he said on Wednesday in a speech before the National Press Club.

Prime Minister Anthony Albanese said on Wednesday that his female colleagues seemed particularly shaken by the attack on Ms. Haines. There had already been an increase in funding for security for members of Parliament in recent years, he said.

“We all have to recognize that politics has got more aggressive,” Mr. Albanese said in a radio interview. “I think the particular impact on women in politics, I think, have got a different form of vilification and aggression toward them.”Victoria Kim is the Australia correspondent for The New York Times, based in Sydney, covering Australia, New Zealand and the broader Pacific region.