Decibel levels rising, Limbaugh notes that, according to dictionary.com, searches for the word "treason" surged by 2900 per cent following Trump's Helsinki press conference. That was largely thanks to a tweet by former CIA director John Brennan accusing Trump of betraying his country by refusing to publicly back his intelligence agencies over Putin on whether Russia interfered in the 2016 election. If anyone should be accused of treason, Limbaugh says, it's Trump's opponents. "When Vladimir Putin goes back to the Kremlin and opens his 14th bottle of vodka of the day and starts consuming it with some of his generals and people, you know what they do?" he tells Sarah. "They start slapping each other on the back, and they tell each other, 'No matter what we plan, no matter what we did, we can’t compare to what the Democrat Party is doing in destroying the integrity of American democracy.' Donald Trump's key media allies, including talkback host Rush Limbaugh, came to his defence after Helsinki. Credit:AP "If you look at elections as the foundation or part of the foundation of American democracy, who is it that’s calling that and the legitimacy of that into question? It’s not the Russians, it’s not Putin, it’s the Democrat Party and the American media! The damage they are doing — you want to talk treason? You want to talk traitorous?"

Brennan – a Barack Obama appointee who once voted for the Communist Party – was an easy target for Limbaugh. But his angry response to Trump's performance in Helsinki was hardly an outlier. As Trump stepped down from the podium on Monday, the immediate consensus across the US political establishment was that the world had witnessed something truly momentous. "We have never seen anything like this in our modern history," said Carl Bernstein, one of the reporters who broke the Watergate story that led to Richard Nixon's downfall. "We have serious people – privately and publicly, Republicans and Democrats – questioning the loyalty of the President of the United States to his own country." Loading A string of senior Republicans lined up to blast Trump's performance: John McCain called it a "tragic mistake"; Mitt Romney judged it "disgraceful and detrimental to our democratic principles". Referring to the November midterm elections, former FBI director James Comey said: “All who believe in this country’s values must vote for Democrats this fall. Policy differences don’t matter right now. History has its eyes on us.”

Most significant of all was the reaction of Newt Gingrich, a former Republican House leader who is so supportive of the President that he published a book last month extolling his achievements (Trump's America: The Truth about Our Nation's Great Comeback). "President Trump must clarify his statements in Helsinki on our intelligence system and Putin," Gingrich tweeted. "It is the most serious mistake of his presidency and must be corrected immediately." Many wondered whether the US had finally arrived at a tipping point, the moment when Republican voters and members of Congress would decisively break with the President? Republican senator Bob Corker thought so. "The dam has broken," he declared. A day later Trump appeared before reporters in the White House to "clarify" his position: he fully accepted the assessment of his intelligence agencies and the perception he didn't was simply because of a slip of the tongue. He had meant to say he saw no reason why Russia "wouldn't" have meddled in the election, not why they "would" have.

The explanation was greeted with derision: did Trump really think he could get away with such a flimsy excuse? Yes, he did. And based on the evidence so far, he was right. "I am really delighted he took a serious look at it," Gingrich said the next day on Fox News. "He hates to correct himself, it's not who he is, but I think he did the right thing and did it well." Republican senator Marco Rubio agreed: "I'm just glad he clarified it. I can't read his intentions or what he meant to say at the time, and suffice it to say that for me as a policymaker, what really matters is what we do moving forward." Ohio senator Rob Portman said he took the President at his word, as did Orrin Hatch of Utah. "We can't blow everything out of proportion," he said.

By siding with Trump, these senators were perfectly in sync with the Republican base. A poll of 2000 people conducted by website Axios found that 79 per cent of Republicans approved of the way Trump handled his press conference with Putin. Even before he won the Republican presidential nomination, Trump famously declared: "I could stand in the middle of Fifth Avenue and shoot somebody and I wouldn't lose voters." The statement remains just as true today. Indeed, the most remarkable thing about Trump's presidency is how impervious his popularity is to events. Scandals and successes come and go without consequence. Since early 2017, Trump's approval ratings have oscillated between 38 and 42 per cent, with support among Republicans consistently in the high 80s. That's because Trump, for the most part, is delivering exactly what they want. In coming months the Senate will vote on the confirmation of Trump's Supreme Court nominee Brett Kavanaugh, a conservative jurist who is just 53 years old. Many Republicans hope he will eventually overturn the right to abortion. President Donald Trump stands with Supreme Court nominee Judge Brett Kavanaugh and his family in the East Room of the White House earlier this month. Credit:AP

John Dean, who served as White House counsel during Watergate, this week attributed Trump's ongoing support among Republicans to the country's polarised media market, in which defenders like Limbaugh and Sean Hannity dismiss even Trump's self-inflicted errors as a left-wing conspiracy. "Nixon might have survived if he had Fox News and the conservative media that exists today," he told Rolling Stone. "I doubt Trump will be forced from office, even if Mueller has tapes of him talking with Putin about how to rig the election." Just days after the Helsinki press conference you could already see a familiar pattern falling into place. In the Trump era, what feels like an earthquake in the moment is soon revealed to have been little more than a tremor. The exhaustion factor This phenomenon is something Mark Mellman, a veteran Democratic pollster, was reminded of first-hand this week.

Mellman was conducting a focus group with independent voters in a Midwestern town, the type of place where Trump performed strongly in the 2016 election. It was the day after the Helsinki press conference and the media coverage had been relentless. The headline on the front page of town's local newspaper that day was "Treason". Mellman was eager to learn how these unaligned voters felt about it. "Most of them weren't familiar with what had happened," he says. "A lot of swinging voters are simply not paying much attention to politics." Loading Fairfax Media experienced the same thing on Monday afternoon at a bar in Staten Island, a pro-Trump area in New York. While a TV silently played news coverage of the meeting, no one was taking any interest. "I don't care about the politicians," a 60-something man at the bar said. He only wanted to talk about the World Cup and apartment prices.

"People are sick and tired of hearing about Donald Trump," Mellman says, explaining the sentiment that comes through consistently in his focus groups. "They don't want to hear about him 24/7." Mellman understands the fascination with Trump's consistent support among Republican voters. But he thinks it's misleading – particularly when analysing the Democrats' chance of winning back the House in November. "If 20 per cent of your base is disagreeing with you, then that is significant," he says, referring to the Axios poll taken after the Helsinki meeting. "And that base is smaller than it used to be." According to a January Gallup poll, 42 per cent of Americans describe themselves as independents, a greater proportion than identify as Republicans or Democrats. And 62 per cent of independent voters disapproved of Trump's performance in Helsinki, according to the Axios poll. Mellman says Democrats are in a good position to take back the House in November, both because of Trump's low support among swinging voters and enthusiasm among progressives to express their displeasure with Trump.

"Democrats are lining up for a pretty big blue wave. But that will filter through a lot of individual races in different ways. It is entirely possible Democrats could win the popular vote by 7 to 10 per cent and still not take back the House." He says there could well be a repeat of the 2016 presidential election result, where Hillary Clinton won the most votes but not where she needed them. A gift to Republicans If Democrats do win the House, attention will immediately focus on one issue: will they use their majority to impeach Trump? If they do, the issue would be referred to a trial in the Senate, which would vote on whether to remove him from office. After Trump's appearance in Helsinki, Brennan said the President's behaviour exceeded the threshold of “high crimes and misdemeanours” – the vague, highly contested criterion for impeachment in the US constitution.

In January, 66 House Democrats voted to impeach Trump and the idea is wildly popular among Democratic voters, with 77 per cent supporting Trump's impeachment and removal from office. But the consensus among senior Democrats is that the issue is political poison. Loading “I don’t think we should be talking about impeachment," the Democrats' House leader Nancy Pelosi said in April. “On the political side I think it’s a gift to the Republicans." Indeed, conservative groups like the Faith and Freedom Coalition have already used the spectre of impeachment to energise their supporters. “Will you do your part to help stop this coup attempt by the radical anti-Christian left and the media against our duly elected President?” the group said in a recent flyer.