The violent attack on Speaker of the House Nancy Pelosi's husband comes with just over a week to go before the US midterm elections - a moment when political tensions are coming to the boil.
As if to emphasise this point, just a few hours after news of the assault on Paul Pelosi on Friday local time, the US government distributed a bulletin to law enforcement across the nation. It warned of a "heightened threat" of domestic violent extremism against candidates and election workers driven by individuals with "ideological grievances".
Also today, the US Department of Justice announced that a man from Pennsylvania had pleaded guilty to making multiple phoned death threats against an unnamed congressman - reported to be Democrat Eric Swalwell of California. The threats included telling a staff member in the congressman's Washington office that he was going to come to the US Capitol with a firearm.
Paul Pelosi, 82, was taken to a San Francisco hospital where he underwent surgery for a skull fracture and injuries to his right arm and hands, a spokesperson for the House speaker said in a statement. Doctors expect her spouse to make a full recovery, the statement said.
The man arrested at the scene was identified as David Depape, 42, who was also taken to a hospital.
Online sheriff's records showed he was booked into the San Francisco County Jail on suspicion of attempted murder, assault with a deadly weapon, elder abuse, battery, burglary, and other felonies. The booking may have been conducted in absentia, as San Francisco Police Chief William Scott later told reporters Depape was still hospitalized.
CNN is reporting that Depape posted memes and conspiracy theories on Facebook about Covid vaccines, the 2020 election and the January 6, 2021, attack on the Capitol.
DePape posted links on his Facebook page to multiple videos produced by My Pillow CEO Mike Lindell falsely alleging that the 2020 election was stolen, CNN said .
President Joe Biden called the attack on Paul Pelosi "despicable" and denounced those who spread lies about stolen elections for corroding the political climate and contributing to politically motivated violence.
"Enough is enough is enough," Biden told supporters in Philadelphia. "Every person of good conscience needs to clearly and unambiguously stand up against the violence in our politics, regardless of what your politics are."
"Democracy is literally, not figuratively, on the ballot this year," said Biden, who warned about the dangers of extremism in an impassioned speech in Philadelphia last month.
CNN reported that Paul Pelosi had called emergency-911 and spoke in "code," not saying directly that he was under attack but leading the dispatcher to conclude something was wrong.
Politico, citing a person familiar with the situation, reported separately that Pelosi had told the intruder he needed to use the bathroom, and then furtively called 911 from there, where his cellphone had been charging.
The police chief credited the 911 operator with using her experience and intuition to "figure out that there was more to this incident than what she was being told" by the caller, leading her to dispatch the call at a higher priority than normal. Scott called her decision "life-saving."
These wailing klaxons of a political system in peril come as Republicans and Democrats frame the upcoming midterm voting, which will determine which party controls Congress next year, as a pivotal moment in American history.
Republicans warn this is the last chance to put a check on Democrat Joe Biden's presidency. Democrats say American democracy itself is at stake because of the numerous Republican candidates who have refused to accept the results of the 2020 presidential election.
And the rhetoric comes at the culmination of what has been a steady drumbeat of violence - and violent threats - that has been building all year.
Death threats
In Arizona, there have been multiple reports of masked individuals with firearms staking out ballot drop boxes, ostensibly to monitor the sites for election fraud. They've posted photographs of individuals casting their ballots on right-wing social media sites and encouraged others to join their efforts.
In June, a man was arrested near the home of Supreme Court Justice Brett Kavanaugh. He had travelled to the Washington suburb from California and called police after he arrived to tell them he had a firearm and intended to kill the conservative justice.
The following month, Republican candidate for governor, Lee Zeldin, was attacked while on stage during a campaign rally. Congresswoman Pramila Jayapal, a liberal leader in the Democratic Party, was threatened by a man with a handgun outside her Seattle home. He was subsequently charged with felony stalking.
Republican congresswoman Marjorie Taylor Greene has had police respond to her home six times based on anonymous hoax calls. The practice, called "swatting", is used to try to provoke a confrontation between the target and law enforcement. She has also been the target of numerous death threats.
Partisan violence - and the threat of it - is nothing new in American politics, of course. The bloodiest recent attack occurred five years ago, when a man with multiple weapons opened fire on Republican politicians playing baseball at a city park. Five were injured, including one critically - second-ranking Republican in the House of Representatives, Steve Scalise of Louisiana. That, however, was an isolated incident.
Keeping politicians safe
Data provided by the US Capitol Police suggests a violent wave is building. The number of cases involving threats against members of Congress has increased every year since 2017. In the first three months of 2022, the department has documented more than 1800 incidents.
In response, Capitol Police announced in July that it would cover up to $10,000 for security upgrades in the homes of congressional legislators.
There are 435 members of Congress, however. They regularly travel to and from their homes around Washington and from the nation's capital to their homes across the nation. A motivated individual fixated on violence will be able to find a way to strike against a targeted politician - or their family.
With Nancy Pelosi thousands of miles away in Washington, there was no police security provided for Paul Pelosi at their San Francisco home. He was not the intended target, but he became the victim.
Before the attack, the suspect is said to have asked, "Where is Nancy?" - the phrase harkening back to the 6 January assault on the US Capitol, when a man roamed the halls of the Capitol, calling out: "Where are you, Nancy? We're looking for you."
Politicians on both sides of the nation's partisan divide have expressed their sympathy for Pelosi and called for a cooling of the rhetoric. It is a task that is easier said than done, however.
With a population encased in political bubbles of social media and news outlets that reinforce their existing political beliefs and fears, individuals will continue to be tempted by extremism and violence.
And when they go looking for the politicians they read about and see on television - ones they are told are enemies of the nation and threats to democracy - they will be able to find them.
- BBC/Reuters