The fallout from Special Counsel Robert Mueller's report, is threatening to redefine the legal and ethical standards that have constrained the American presidency.

And, it suggests that few, if any, of the traditional guardrails that have kept US President Donald Trump's predecessors in check remain for this president and possibly those who will follow him.

Trump repeatedly tried to undermine the Russia investigation, but the Special Counsel overseeing the probe declined to say whether he broke the law - and the Attorney-General declared that he had committed no crime.

Trump's campaign showed a willingness to work with a foreign power - something his personal lawyer now insists is perfectly okay.


And Trump has furiously rejected congressional scrutiny of his presidency - taking the unprecedented step today of suing a Democratic committee chairman to block a subpoena for his financial records.

"The most disturbing part of the picture that's been drawn about norms is there is now a crumbling consensus about what they are," said Bob Bauer, White House counsel under President Barack Obama.

"The Republican defence of Trump has muddied the congressional response, so it now appears that even a president who is a chronic liar, who tried to obstruct justice, who instructed his White House counsel to fabricate evidence, has not apparently conducted himself in a way that everybody can agree violates the norms."

Democrats had hoped that Mueller's investigation into Russia's interference in the 2016 election would serve as a check on what they view as Trump's rampant abuse of power.

But Mueller's team found there was no conspiracy between Moscow and the campaign while concluding that it could not render a judgment on whether Trump criminally obstructed justice because of government guidelines about indicting a sitting president.

This left an emboldened, if still livid, Trump to proclaim "complete and total EXONERATION" despite the report's numerous details of the President's efforts to end or stymie Mueller's investigation.

Trump's aides and supporters have brushed off the details in Mueller's report that show the President tried to stop or stymie the Special Counsel's investigation, with even Attorney-General William Barr describing Trump's actions as understandable given his anger over the probe. They have portrayed Democrats as sore losers for refusing to accept that Mueller did not declare Trump had committed any crimes.

But the aftermath of Mueller's report, as well as Congress's overall inability to help serve as a check on Trump, has potentially created a precedent in which it remains unclear where the current lines are on presidential behaviour.


Frank Figliuzzi, a former FBI assistant director, said that the combination of an Attorney-General who "comes at this from a legal philosophy of very broad executive powers" and a president who "is more interested in an imperial presidency" has created a troubling dynamic "where we may have three equal branches of government but one branch - the executive one - is more equal than the others."

Nick Akerman, a former federal prosecutor who served as a member of the Watergate prosecution team, also criticised Barr for stepping in to declare no crime had been committed when Mueller's report seemed to leave this decision up to Congress.

"It's problematic because you've got a renegade Attorney-General who's basically doing everything he can to twist the law, to make it sound like what Trump did is not a crime," Akerman said. "It makes it a lot harder for somebody else, after Trump leaves office, to prosecute him based on the facts Mueller has found - that he obstructed justice."

Yesterday, Trump lawyer Rudy Giuliani seemed to further define downward acceptable presidential conduct, telling CNN that "there's nothing wrong with taking information from Russians" - a government the intelligence community and Mueller have concluded interfered in the election to sow discord in the US.

He said the issue was not one of "immorality," arguing that nearly every presidential campaign in history has engaged in some sort of immoral or unethical behaviour. But, he added, he personally would have advised against accepting information from the Russians, "just out of an excess of caution".

The repercussions of Mueller's report, as well as the unabashed victory lap by Trump and his allies, has created a particular conundrum for Democrats, who are still grappling with the politically-fraught question of whether to move forward with impeachment proceedings that are almost certain to die in the Republican-controlled Senate.

Senator Elizabeth Warren, was the first major Democratic presidential candidate to call for Trump's impeachment, in a series of Twitter posts.

"To ignore a President's repeated efforts to obstruct an investigation into his own disloyal behaviour would inflict great and lasting damage on this country, and it would suggest that both the current and future Presidents would be free to abuse their power in similar ways," she wrote.

But Democrats generally remain mixed on how to proceed. Many are reluctant to waste political capital on a mission - impeaching Trump - they believe has little chance for success. But they are also mindful that by not condemning the President's behaviour, they may be seen as tacitly condoning it and helping lower the standards for future occupants of the Oval Office.

"I think even if we did not win possibly, if there were not impeachment, I think history would smile upon us for standing up for the Constitution," House Oversight Committee Chairman Elijah Cummings said on CBS while noting he was not yet ready to begin impeachment proceedings.

House Speaker Nancy Pelosi told her members that they had no immediate plans to open impeachment proceedings but would continue to investigate Trump, according to officials on the conference call.

White House aides said they believe the report will have little long-term political damage because most of the damaging stories were already known - and that even some of the President's ardent supporters do not view him as a paragon of morality.

Several advisers added they expect Mueller's conclusions to cost Trump few votes.

"I don't think there was a whole lot of information that was new that had not been reported on previously or discussed in a public setting," said Raj Shah, a former White House spokesman who now advises the campaign. "It almost seemed like the summary of the last two years of the public debate. I don't think this report gives any momentum to those who want to see the President impeached."

Shah added that Trump voters are unlikely to punish the President for fighting back against the Mueller's probe. "The broad notion that the President was disgruntled with and unhappy with an investigation targeting his legitimacy out of the gate - they afford him the right to be upset about it," he said.

Mueller's finding that there was no conspiracy between the Trump campaign and Russia has now become a key talking point heading into Trump's re-election bid, with his political apparatus planning to target both the investigators and the news media that covered the investigation.

Trump has told White House aides that they should expect continued subpoenas and calls for testimony on Capitol Hill, and that he hopes to use that to portray the Democrats as overzealous partisans.

And, unlike during Mueller's investigation, the President is unlikely to allow all of his current and former aides to testify publicly, according to White House officials.

The White House has already made it clear it plans to fight nearly every request for documents and testimony from Democratic committees, and a senior White House official said the report allows them to be more emboldened pushing back against House Judiciary Committee Chairman Jerry Nadler and other congressional investigators.

Current and former aides say they do not expect Trump to change his behaviour, saying he is unlikely to be responsive to anything other than political pain in the form of a real revolt from Republican leadership or a sharp drop in poll numbers.

George Conway, a Republican lawyer and frequent Trump critic who is married to one of the President's senior advisers, said that the President may soon feel political repercussions, arguing he should be performing better in public opinion polls giving the strength of the economy.

"Everybody knows that there is not this overwhelming urge and supermajority of public support to remove this guy from office," Conway said.

"He is his own worst enemy. He's the reason he's not at 50 or 55 per cent plus with the economy going the way it is. That tells you something about how damaging this has been to him."

Trump was showing no signs of backing down. Asked at the White House Easter Egg Roll if he was worried about impeachment, he replied: "Not even a little bit."

And pressed on the portrait that emerges in the Mueller report, of White House aides disregarding his directives and at times working to scuttle his most dangerous impulses, the President was adamant.

"Nobody disobeys my orders," Trump said.