Will Helsinki change the course of Trump's presidency?

It's been a tumultuous week for Donald Trump, as his White House scrambled to handle the political fallout from his summit with Russian President Vladimir Putin. But has his performance done lasting damage to his presidency?

Stop me if you've heard this one before.

Donald Trump says or does something controversial. Pundits and politicians across the political spectrum offer varying shades of condemnation or disapproval.

The White House makes efforts to address concerns and offer explanations. Mr Trump regains his footing and goes on the attack against the "fake news media" and an establishment that wants to destroy his presidency.

Then polls come out showing that nothing has changed.

It's a pattern that played itself out in the days after Mr Trump's first travel ban led to chaos in US airports. And after he fired FBI Director James Comey. And after he expressed sympathy for the white nationalists who clashed with protesters at a rally in Charlottesville.

It was a regular feature of his presidential campaign, whether it was the airing of the Access Hollywood tape during which he boasted of making unwanted sexual advances on women, feuded with a Hispanic beauty pageant contestant and the Muslim parents of a slain US soldier or questioned the patriotism of former prisoner of war and current US Senator John McCain.

The outcry after Mr Trump's Helsinki press conference, during which he said both the US and Russia were to blame for tension between the two nations and cast doubt on his own administration's assertions that Russia meddled in the 2016 US election, was quite familiar.

Democrats and liberal commentators pounced. Never-Trumpers on the right were quick in their condemnations. Republican officeholders who have been on-again, off-again critics were back on the prowl.

"The dam has broken," Republican Senator Bob Corker of Tennessee said. "What we've got to figure out is how do we deal with it."

Other politicians, like House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell, issued statements of disapproval, albeit without mentioning the president's name.

Even reliable Trump supporters were largely silent - or unhappy. Former House Speaker Newt Gingrich, for instance, called Helsinki "the most serious mistake of his presidency and must be corrected - immediately".

And that's what Mr Trump did on Tuesday, reading a written remark in which he "clarified" that he had misspoken in Helsinki and giving multiple television interviews where he affirmed that he believed the conclusions of his intelligence team that Russia was - and is - engaged in ongoing attempts to disrupt US democracy.

Concurrent with the White House clean-up operation was Mr Trump's continued insistence that the Helsinki summit had been a "great success", obvious to those at "higher levels of intelligence" and only doubted by the US media, which he once again called the "enemy of the people".

Such an attack on the free press was once a headline-generating event, but now - at least the fourth time the president has uttered the phrase - it elicits barely a shrug.

There still was some belief that this time, however, could be different. That Mr Trump had finally gone too far for American voters to stomach.

"If you always predict that this isn't the straw that will break the camel's back, you'll almost always be right but will also always miss when the straw breaks the camel's back," political analyst Nate Silver tweeted.

But then it's usually something bigger than straw that breaks the camel's back. And most camels die of causes other than a broken back - or die long after their straw-carrying days are over. By mid-week, Republicans in Congress were coming around. Mr Corker's broken dam had apparently been patched back together again, and the Tennessee senator said Mr Trump's damage control efforts were "a step forward" and he was glad they had occurred.

Then the post-Helsinki polls began dropping, and what they showed was that while the public at large wasn't happy with the president's performance, his Republican base was holding firm - as it has through good times and bad. Especially through the bad.

In a HuffPost/YouGov survey, 83% of Trump voters approved of Mr Trump's handling of the summit, compared to 40% of the public. A CBS poll found that while only 32% of Americans approved, that number jumped to 68% among Republicans. Meanwhile, 61% of the public was concerned about Russian interference in the upcoming 2018 mid-term elections, but that number dropped to 38% among Republicans.

In fact, as McKay Coppins of the Atlantic noted, some in Mr Trump's Make America Great Again (MAGA) coalition appear at peace with the possibility of Russian meddling in 2016, since it benefited their man's cause.

"Skimming #MAGA Twitter, it's easy to see the outlines of the pro-Russian-meddling argument emerging," Coppins writes. "America interferes in other countries' elections, so it can't be that bad; exposing Democrats' hacked emails was a victory for transparency; keeping Clinton out of office was so urgent and important that it warranted some foreign intervention."

As the Trump-Russia week drew to a close, the president once again stunned the political world by announcing that he had already extended an invitation to Mr Putin to visit the US sometime in the autumn. Coming on the heels of a week of bad press, it seemed like a risky move - and yet it was classic Trump.

Like the shock announcement of a meeting with North Korean leader Kim Jong-Un earlier this year, it caught even those in his administration off-guard. But it succeeded in changing the narrative, prompting speculation about what might happen next - not further chewing on the bones of Monday's summit.

What better way for Mr Trump to show he truly believes that Helsinki was a "great success", as he tweeted earlier this week, than to start planning its sequel?