By John Wagner

US President Donald Trump pardoned a tough-on-immigration Arizona sheriff accused of racial profiling.

He threatened a government shutdown if Congress won't deliver border wall funding.

He banned transgender people from serving in the US military.


And he is expected to end a programme that shields from deportation young undocumented immigrants who consider the United States home, but with a six-month delay.

These and other moves - all since Trump's widely repudiated remarks about the hate-fuelled violence in Charlottesville, Virginia, less than a month ago - are being heartily cheered by many of his core supporters. But collectively, they have helped cement an image of a president, seven months into his term, who is playing only to his political base.

Trump's job-approval numbers remain mired in the 30s in most polls, and several new findings last week gave Republicans interested in expanding the party's appeal fresh reason to worry. A Fox News survey, for example, found that majorities of voters think that Trump is "tearing the country apart" and does not respect racial minorities.

The findings come ahead of what could be another turbulent stretch in Trump's presidency.

He and Congress are seeking this month to keep the government funded and raise the nation's debt ceiling, amid a Russia probe that is gaining steam and continuing feuds between Trump and fellow Republicans.

In interviews, White House aides and advisers played down concerns about Trump's standing in the polls, with some suggesting his numbers are more a reflection of broader disgust with Washington. Some also said it is important to keep Trump's base energised at a time when he has yet to deliver on legislative promises and has seen some erosion among key constituencies, including working-class whites.

At the same time, Trump allies pointed to his visits to areas ravaged by Hurricane Harvey - the latest on Sunday as he sought to show empathy for victims and emergency responders in Texas and Louisiana - as evidence of a president seeking to unite the country. The crisis in North Korea presents another test of Trump's ability to bring the nation together.

And heading into the northern autumn, Trump aides and advisers argue that a major push for tax cuts has the potential to boost Trump's standing among Americans well beyond his base.

Though there is no concrete plan and many thorny issues remain, Republicans in Congress are hoping to rally behind legislation that would demonstrate an ability to govern that so far has been elusive during Trump's tenure.

"Voters are very sceptical it will happen," said Tony Fabrizio, who served as Trump's pollster during last year's election. "If the President can get a tax-reform package passed, it will confound their expectations and be a huge win."

Trump plans to pitch the idea of tax legislation this week in North Dakota, marking the second trip in as many weeks aimed at building momentum for both corporate and personal income tax cuts. Both this visit and one last week to Missouri are being staged in states Trump won last year and where there is a Democratic senator whose support could be crucial to the fate of any legislation.

For an unorthodox president, such trips are fairly traditional ways to build pressure on Congress to act and have given more mainstream Republicans some reason for hope about Trump's engagement following the GOP failure to pass healthcare legislation.

In the meantime, though, many in the GOP are openly questioning Trump's words and actions on issues that are divisive, even among Republicans. Trump's assertion that many "fine people" marched alongside white supremacists in Charlottesville drew condemnation across party lines.

And some in the GOP say other recent choices appear designed to bolster the President's standing only among his most loyal supporters. In recent weeks, Trump has continued his practice of holding campaign-style rallies in states he won, creating an echo chamber of support with his most loyal backers.

"It's almost as if he's the pilot of a plane that's in a terrible downward spiral and he's insisting on continuing to do things to make it worse," said John Weaver, who was chief strategist for the 2016 presidential campaign of Governor John Kasich, (R). "You can't govern like that, and you can't win re-election like that, and you can't take your party into the 2018 midterms like that."

Recent polling has underscored the narrow band of support Trump enjoys for some of the policies he is advocating.

Only 34 per cent said Trump did the right thing by pardoning former Maricopa County sheriff Joe Arpaio, while 60 per cent said he did the wrong thing, according to an NBC/SurveyMonkey poll released last week. Arpaio, a major Trump booster during last year's campaign, was convicted of criminal contempt for ignoring a federal judge's order to stop detaining people because he merely suspected them of being undocumented immigrants.

In the same survey, only 30 per cent said they oppose the policy begun under President Barack Obama that has provided two-year work permits to nearly 800,000 immigrants known as "Dreamers" who have been in the country illegally since they were children. Sixty-four per cent voiced support for the policy, which Trump has threatened to dismantle. He plans to announce his intentions on Wednesday.

Some leading Republicans, including House Speaker Paul Ryan, urged Trump not to rescind the programme.

Since taking office, Trump has repeatedly taken actions with little crossover appeal to Democrats or independents but strongly backed by Trump voters, including efforts to ban entry to the United States from a group of majority-Muslim countries and pull out of the Paris climate change accord.

Polls have also showed majorities of Republicans favouring a border wall but only small percentages of Democrats in support. In the Fox News poll, only 18 per cent of overall voters thought it was a good idea to shut down government to force the issue - an idea Trump appears to have backed away from, at least for now.

Trump boosters say he is merely following through on his campaign promises.

"He is part of his base," said Barry Bennett, a Republican strategist who advised Trump during the general election. "When he does these things, the base likes it, but he's doing it because he believes it."

Others suggest there is more political calculation involved.

"He's stoking his base with rhetorical messaging in part because it's taking longer than hoped to get some of his major campaign promises checked off," said one Republican strategist close to the White House.

Trump associates say it's also important to keep the base energised so that they turn out for Republicans in next year's midterm elections and for Trump's re-election bid. Some of Trump's supporters last year were not regular voters.

Trump's job approval rating dipped to 34 per cent last week in Gallup's daily tracking poll, matching his low mark for the year. Recent polls have showed erosion among Republicans and subgroups such as white working-class voters, who were key to Trump's election last year over Democrat Hillary Clinton. A poll by Fabrizio's firm, for example, showed the number of Republican and Republican-leaning voters who disapprove of Trump's performance rising from 19 per cent in June to 25 per cent in August.

Fabrizio, who said he has not done work for Trump since the election, characterised the erosion as "negligible" and pointed to a Fox News finding that 96 per cent of Trump voters remain satisfied with their vote from last year. That is higher than the 93 per cent of Clinton voters who remain satisfied.

Ed Goeas, a Republican pollster and strategist, argued that after an uptick following the election, Trump's favourability has basically fallen back to where it was during a campaign season in which voters faced a choice between two largely unpopular candidates.

The good news for Trump, Goeas suggested, is that many people who don't like Trump are turned off by his personality rather than the issues he's pushing. That creates the possibility of broader acceptance if he's successful in pushing tax cuts.

Charles Franklin, director of the Marquette Law School Poll, said the deterioration in Trump's overall job approval has been fairly typical of recent presidents during their opening stretch in office. What's different, he said, is that Trump started from a much lower point that other presidents.

Even Trump's detractors acknowledge that he seems to have a core group of supporters unlikely to abandon him regardless of what transpires in Washington. That in part explains Trump's frequent travel for campaign-style rallies, said Rick Wilson, a GOP strategist and frequent Trump critic.

"There's nothing he's got right now except adulation from his base," Wilson said. "He could eat a live baby on stage and they'd forgive him. He can do no wrong."

A Monmouth University poll released last month showed about a quarter of respondents saying that not only do they approve of Trump, but that they also "cannot see Trump doing anything that would make them disapprove of him".

Mary Anne Marsh, a Democratic consultant, said Trump appears to be battening down with his base in anticipation of fallout from the special counsel's investigation into Russian meddling in last year's election. If things get rough for Trump, the defence of core supporters becomes even more crucial, she said.

"If you look at it through that lens, it makes sense," Marsh said. "Any other president would have spent their time trying to expand their support."