How did we get to this point? When did our public standards fall so low that charges of physical assault were met with the sound of crickets across the Republican side of Congress?

The assault charge now standing against Montana’s congressional candidate Greg Gianforte is itself a disqualifying moment for anyone attempting to enter elected office.

You can hear for yourself what happened to Guardian reporter Ben Jacobs when he asked Gianforte a simple question about the impact of the Republican repeal of Obamacare. Make up your own mind about Gianforte’s behavior.

Republican candidate charged with assault after 'body-slamming' Guardian reporter Read more

But there’s something even more poisonous that threatens our politics today, and it has spread far beyond Montana.

You can trace back the decline in our politics to a single campaign and a single candidate, who riled up his crowds to turn on the press and hurl abuse in their direction.

That’s the same candidate who longed for the days when he could punch protesters in the face. Sure enough, his supporters ended up punching people in the face.

Fortunately the rule of law still endures in the courts, where a Kentucky judge recently denied the candidate’s claims that he was just exercising his rights to free speech and couldn’t be sued for inciting violence.

The candidate is of course now president of the United States, who calls the media “the enemy of the American people.”

This is not a small development in the long history of shocking Trumpisms.

You don’t need to take the Guardian’s word for it. Here’s the opinion of William McRaven, the former special ops commander and architect of the raid that killed Osama bin Laden: “This sentiment may be the greatest threat to democracy in my lifetime,” he told journalism students at the University of Texas earlier this year.

Yes, journalists are important. So important that the founding fathers cited the freedom of the press in the first amendment to the constitution. At the start of the Bill of Rights, it’s sandwiched between the freedom of religion and the right to petition the government.

Journalism is so important that the Massachusetts constitution says this: “The liberty of the press is essential to the security of freedom in a state: it ought not, therefore, to be restrained in this commonwealth.”

It’s needless to say this, but given recent events, it’s also sadly necessary. Public threats and violence towards journalists – whether from candidates or elected officials – are clearly an attempt to restrain the press. And if you restrain the press from asking questions, you are restraining the people from asking the same questions of their own government.

What is the right response to this kind of behavior?

First, journalists need to stick together, like this crew from Fox News who published their account of what happened between the candidate Gianforte and Jacobs.

“Gianforte grabbed Jacobs by the neck with both hands and slammed him into the ground behind him,” they wrote. “Faith, Keith and I watched in disbelief as Gianforte then began punching the reporter. As Gianforte moved on top of Jacobs, he began yelling something to the effect of, “I’m sick and tired of this!”

Another defense of the press and civil liberties came in Montana itself, where the three newspapers that endorsed Gianforte have all withdrawn their support for the candidate on this, the final day of the election.

Second, elected officials who still believe in the constitution need to stick together. That includes Republican leaders who want to hold on to their jobs.

A decade ago, as the wheels were dropping of the bus known as President Bush’s second term, the Republican party was staring at a wave election.

The public had rapidly lost faith in both the newly elected president and the Republicans controlling Congress – not just because of the war in Iraq, but also because of failures on domestic legislation like immigration reform and curbing social security.

To cap it all, the Republican party was embroiled in a series of shocking stories including the Jack Abramoff lobbying scandal, pork-barrel spending by Alaskan senator Ted Stevens, campaign finance irregularities by House majority leader Tom DeLay and a sexting scandal involving deputy whip Mark Foley and teenage congressional pages.

The stench of sleaze was overwhelming, and Democrats enjoyed an 11-point advantage in the generic congressional polls ahead of an election in which they ultimately took back both the House and the Senate.

Today, Democrats have a six-point lead in the generic congressional polls, 18 months away from voting day. That’s plenty of time for the Russian investigations to work their way into the public consciousness.

It’s also plenty of time for Republican leaders to stop the rot by condemning violence, and protecting the rights of the free press. They might even start by taking the investigations into Russian collusion seriously.

For that to happen, the voters need to signal more clearly what they think. They could start today in Montana, where Gianforte has a 14-point lead in a state that Trump won by 21 points six months ago.

They could start by saying they’re sick and tired of candidates who behave like this.