The silent and pivotal reality of today’s US politics is the continuing strength and resilience of Don­ald Trump’s electoral base.

Reg­ardless of whatever controversy or fiasco engulfs the Trump White House, the base is largely immovable as mirrored in polls that move routinely between 38 per cent and 40 per cent of voters. Indeed, Trump has been reported as claiming he could shoot someone on Fifth Avenue in New York City and his base would not move.

This prompted the New York Daily News to publish a cartoon on its front page in the turmoil following the Helsinki summit showing Trump and Vladimir Putin promenading on Fifth Avenue, while Trump shoots an innocent Uncle Sam. The headline read: “Treason.”

About 90 per cent of Republican voters express satisfaction with the Trump presidency. In a deeply divided American body politic, this apparently unshake­able faith in the 45th US President is an overriding reality that at once affords Trump both licence and leverage. He is the dominant force in Republican politics, not the Speaker or the Senate majority leader, and certainly not the wealthy Koch brothers.

The power to tweet is directed always at moving or mobilising the base, no matter how absurd the presidential charge or claim.

The power to tweet is directed always at moving or mobilising the base, no matter how absurd the presidential charge or claim, such as the recent throwaway line that the Russians will intervene in November’s mid-term elections to assist the Democrats.

Barack Obama is right. We do live in strange and uncertain times. Truth and lies are interchangeable commodities.

To establish why the Trump base has proved so resolute, it is instructive to turn back to a much darker period in American politics; to McCarthyism in the early 1950s. There is a direct and decisive link between that period and now, in the person of Roy Cohn. Cohn was a trusted adviser to the junior Republican senator for Wisconsin, Joseph R. McCarthy. Cohn was also an influential mentor to Trump, who learned from Cohn’s street-fighting ways how to win in the New York property markets.

McCarthy was a demagogue for whom the truth was of little or no consequence. A practitioner of the brutal smear, he elevated US postwar concerns about Soviet communism into hysteria, claiming there were red agents everywhere in Washington, DC.

McCarthy’s principal weapon was the unsubstantiated allegation of treason directed at respected and leading figures in the Truman administration, including General George Marshall and secretary of state Dean Acheson.

McCarthy’s recklessness, including ruthless manipulation of the new medium of television, eventually led to a bipartisan censure in the US Senate, with senator Prescott Bush, father and grandfather of future US presidents, prominent among McCarthy’s critics. The censure was carried on bipartisan lines 67-22.

But, as Jon Meacham notes in his masterly new work, The Soul of America,in the national opinion poll immediately following, some 34 per cent of Americans still believed McCarthy was on the right track. McCarthy’s base support was cultural and religious, unmoved by elite opinion. The same may be said of Trump.

Trump’s constituency, according to research by Vanderbilt University, is essentially traditionally Republican but there are those who demand the satisfaction of “red meat” from their President.

Hence, Trump’s rallies are a continuation of his 2016 campaign, whereby the President is forever running against “crooked” Hillary Clinton, or battling house minority leader Nancy Pelosi, or senator Elizabeth Warren (Democrat, Massachusetts) or perhaps Trump’s newest outspoken adversary, congresswoman Maxine Waters of California.

The gender of those attracting presidential ire is lost on nobody.

One shift in American voter opinion could yet prove disastrous for Trump 2020. In 2016, Trump led Clinton among women voters by 20 points. He now trails by the same margin.

But the rolling maul of Trump’s rallies or the abuse in his tweets should not obscure two realities.

First, Trump’s standing among independent voters remains respectable.

This is due to the fact that, second, his objective record, with a buoyant economy, tax cuts, conservative justices such as Neil Gorsuch or Brett Kavanaugh nominated to the Supreme Court, regulatory rollback and repeated forays on “The Wall” at the border with Mexico, directly reflects his campaign promises.

The theatre of the Oval Office signing of Trump’s executive orders is designed to demonstrate that this President, unlike others, including Republicans, keeps faith with his base, which remains vital to his incumbency.

The theatre of the Oval Office signing of Trump’s executive orders is designed to demonstrate that this President, unlike others, including Republicans, keeps faith with his base, which remains vital to his incumbency.

For it is a powerful illustration to recall that when Richard Nixon resigned the presidency in 1974 he argued that his base in congress had collapsed. It had, but Nixon had lost the country and powerful Republican senators, such as Barry Goldwater of Arizona, had abandoned him.

Trump is constructing a narrative that will permit him to contemplate his own version of Nixon’s “Saturday night massacre”, which involved firing Water­gate special prosecutor Archibald Cox while accepting the resignations of his attorney-general Elliot Richardson and his deputy, Bill Ruckelshaus. For many Americans this was the final straw but, given today’s loyalties, perhaps not for Trump.

Trump’s narrative holds Robert Mueller’s probe of Russian intrusions in the 2016 election is a witch-hunt by Democrats, by a conflicted prosecutor and, quite extraordinarily, represents an obstacle to improved US-Russian relations.

As Mueller’s investigation draws closer to the Trump family, especially son Donald, the pressure to fire the special counsel will intensify. But to do so, in all probability Trump will need also to fire his Attorney-General Jeff Sessions and his deputy Rod Rosenstein, who indicted the 12 Russian intelligence officers over 2016 cyber intrusions.

Recently, at an Aspen security conference, Rosenstein delivered a defiant address on confronting malign foreign influences in US politics. This was as Trump was openly refusing to acknowledge the history of Russian interference. Rosenstein’s body language was unambiguous. Accord­ing to those who know him, Rosenstein’s respect is for the law and his loyalty is to the republic. Rosenstein may prove to be the Richardson of this administration.

Trump’s base, like that of ­McCarthy, will remain with him. Ultimately, though, ­McCarthy was overwhelmed by hard political realities that proved far more formidable than sentiment.