There were signs on Wednesday (AEDT) that some Trump allies were nervous about sparking a deeper cultural debate in the campaign's final stretch, particularly with some critics alleging that hostile political rhetoric has played a role in encouraging violence.

House Speaker Paul Ryan, typically loath to criticise Trump, swiftly expressed scepticism about the president's view that he could limit the constitutionally guaranteed citizenship rights of anyone born on US. soil. Later, Representative Steve Stivers, the head of the House Republicans' campaign arm, condemned Representative Steve King, one of the most outspoken immigration critics in Congress, for supporting nationalist politicians, tweeting: "We must stand up against white supremacy and hate."

Kanye West, a prominent African-American musician who embraced Trump in a much-hyped Oval Office meeting this month , tweeted: "My eyes are now wide open and now realise I've been used to spread messages I don't believe in. I am distancing myself from politics and completely focusing on being creative!!!"

Yet many Republicans voiced support for Trump's broader goal of limiting illegal immigration, and the president's decision to put the issue at the forefront reflected the extent to which he has changed the rules of engagement.

While Republicans have long criticised Democrats for emphasising "identity politics" in their courtship of ethnic minorities to win elections, Trump is now taking steps seemingly designed to mobilise his heavily white base. And with the past week's violence coming after three years of warnings from critics that Trump was stoking racism, his unwillingness to tone down his nationalist appeals is reviving concerns about his closing strategy.

Nancy Pelosi: "Clearly, Republicans will do absolutely anything to divert attention away from their votes to take away Americans' health care." AMY BETH BENNETT

"It's very risky," said Alex Conant, a longtime Republican consultant. "Obviously Republicans who show up at his rallies, they love it. But he's not going to suburbia, because a lot of those policies don't play well with suburban Republicans. It's frankly why our House majority is at risk."

"Trump is single-mindedly focused on turning out his base," Conant added. "If you're in a deep-red state, that's great. If you're in a purple state or a swing district, it's a problem."


The approach that Trump and his allies are taking sets up a campaign in which the two parties are not so much debating as talking past one another. Trump continues to hammer away on immigration with little response from Democratic leaders, while Democrats remain almost solely focused on health care.

Trump has tried out other issues, including floating a new tax cut last week, but he rarely strays too far from immigration, the fiery topic that has animated him, and his loyal base, from the time he announced his presidential campaign in 2015.

Ramped up rhetoric

A week ago he openly embraced the racially loaded word "nationalist" to describe his political philosophy. Even as a shocked nation turned toward a pipe-bomber from Florida and a gunman in Pittsburgh, the president ramped up his rhetoric and the bluntness of his proposals to try to regain the spotlight.

First, he sounded alarms about the migrant caravan marching through Mexico, claiming that it was an "invasion" even though it remained nearly 1600 kilometres away. Then, he ordered 5,200 US troops to the southern border.

On Tuesday - a day when he visited grief-stricken Pittsburgh - he unveiled a constitutionally dubious proposal to end the right of US citizenship for children born in the United States to non-citizens. He also talked about building tent cities for migrants.

"You cannot end birthright citizenship with an executive order," Ryan said during a radio interview with Kentucky-based station WVLK. "We didn't like it when Obama tried changing immigration laws via executive action, and obviously as conservatives we believe in the Constitution."

Representative Ryan Costello said Trump was engaging in "political malpractice" and putting suburban Republicans in competitive districts at risk.


"So now POTUS, out of nowhere, brings birthright citizenship up," he wrote on Twitter. "Besides being basic tenet of America, it's political malpractice."

Bob Hugin, a Republican and Marine Corps veteran running against Senator Robert Menendez in a race that Democrats have been concerned about, also denounced Trump's proposal.

"The President is wrong to end #BirthrightCitizenship," he wrote on Twitter. "I took an oath to defend the Constitution including the 14th Amendment. We're a nation of immigrants made better by the diversity of its people, especially in NJ. We need compassionate comprehensive immigration reform now."

But other Republicans were fully embracing Trump and his political brand of attacking his opponents and using racial undertones.

The National Republican Congressional Committee has been running an ad in a Minnesota congressional district showing George Soros, the Jewish philanthropist and Democratic donor who was the target of one of the pipe bombs sent by mail last week, behind stacks of cash. In Connecticut, a Republican state Senate candidate mailed campaign literature that depicts his Democratic opponent, Matthew Lesser, holding a fistful of cash near his mouth. Lesser is Jewish, and the ad has triggered complaints of anti-Semitism.

Democrats have largely avoided engaging with Trump, issuing brief statements about his immigration proposals but then quickly turning toward health care.

"President Trump's new claim he can unilaterally end the Constitution's guarantee of citizenship shows Republicans' spiralling desperation to distract from their assault on Medicare, Medicaid and people with pre-existing conditions," House Minority Leader Nancy Pelosi, said. "Clearly, Republicans will do absolutely anything to divert attention away from their votes to take away Americans' health care."