Republican presidential nominee Donald Trump says he favors "stop-and-frisk." Here's what that means and why the policy is so controversial. (Victoria Walker/The Washington Post)

Donald Trump has amplified his focus this week on a strident nationalist and law-and-order message, emphasizing rhetoric that has fueled his popularity among white working-class voters but which also threatens to antagonize the centrists likely to decide the November election.

In speeches and interviews in recent days, Trump has called for “American hands” to remake the country rather than those of foreigners. He has portrayed Syrian refugees as a cultural threat, not just a security risk. He has also embraced controversial “stop-and-frisk” policing — a tactic championed by some conservatives but opposed in minority communities as a form of racial profiling — and suggested on Thursday that drugs were a major factor in anti-police protests.

Trump’s hard-edged message is at odds with more traditional nominees who tend to use the final weeks of the race to shore up support among voters in the middle of the political spectrum. It also comes at the same time that Trump has been attempting to reach out to minority communities with visits to black churches and charter schools, making for some awkward interactions and scenes.

With less than seven weeks until Election Day, polls show Trump is steadily chipping away at Democratic nominee Hillary Clinton’s once-wide lead. But the electoral math still favors Clinton, putting pressure on Trump to improve his standing in diverse battleground states such as Pennsylvania, which Democrats have claimed in the last six presidential elections.

Trump’s supporters say his “America first” message applies to minorities, immigrants and moderate voters as much as it does to conservative whites.

“It is many of those voters who need the jobs. It’s many of those voters who want to walk the streets in Chicago and feel safe,” said Rep. Chris Collins (R-N.Y.), a Trump backer.

He acknowledged, however, that it’s a provocative pitch. “There’s some controversy in it, but you can’t be afraid of controversy when you’re putting America first,” Collins said.

At a Wednesday rally in Toledo, Ohio, Trump expanded on his usual security-focused objections to letting in refugees fleeing the Syrian civil war, saying that the migrants — most of whom are Muslims — should be blocked for cultural reasons as well.

“This isn’t only a matter of terrorism, but also a matter of quality of life,” said Trump, who has proposed an unspecified vetting procedure to screen out immigrants whose views are incompatible with American values. “We want to make sure we’re only admitting those into our country who support our values and love — and I mean love — our people.”

Trump received loud cheers from the predominantly white crowd.

During the same rally, Trump proclaimed that under a Trump presidency, “American hands will rebuild our nation. Not the hands of people from other nations.”

A supporter of Republican presidential nominee Donald Trump holds a sign before a campaign rally at the Stranahan Theater on September 21, 2016 in Toledo, Ohio. (Angelo Merendino/Getty Images)

Trump has held up sweeping trade deals as a job-killers in Rust Belt states and parts of the South that once thrived with manufacturing jobs but have experienced severe economic decline.

“We can’t continue to be the suckers that allow thousands of companies, millions of jobs to be lost by moving their manufacturing plants and factories to other countries. We can’t do it,” he said in Kenansville, N.C., on Tuesday.

While he has spoken to concerns of many white blue-collar voters this week, Trump has also made a concerted effort to show that he is reaching out to minority communities, promising to devote himself to rebuilding inner cities and saying his economic stewardship would elevate black neighborhoods. The message is aimed in part at reassuring white suburban voters concerned about his history of racially incendiary rhetoric, particularly regarding Mexicans and Muslims.

But the attempts have hit speed bumps. A town hall in Ohio this week hosted by Sean Hannity of Fox News was supposed to be focused on issues facing the black community, but the audience was largely white. Trump continues to speak to mostly white audiences on the campaign trail.

During a Wednesday campaign event at the New Spirit Revival Center in Cleveland Heights, Ohio, several high-profile Trump surrogates — including famed boxing promoter Don King — sought to combat the impression among many voters that Trump is racist.

However, as King introduced Trump, he inadvertently said the n-word while discussing black assimilation, drawing immediate outrage on social media and from black rights groups.

“If you’re a dancing and sliding and gliding n-----, — I mean negro!” King said, catching himself abruptly. “You’re a dancing and sliding and gliding negro. So dare not alienate because you cannot assimilate. You know, you’re going to be a negro till you die.”

Trump also faced a swift backlash Tuesday after he declared that blacks are “in the worst shape they’ve ever been” during the event in Kenansville — a town named after a man whose family owned a slave plantation.

Such botched outreach attempts have fueled accusations from critics that Trump lacks the historical and cultural awareness of the struggles minority voters have faced.

Trump’s championing of “stop-and-frisk,” a controversial policy in which police officers are empowered to stop, question and search individuals they deem suspicious, has also alarmed many African American leaders.

“The policy of ‘Stop & Frisk’ (aka Detain & Dehumanize) is simply profiling for communities of color,” tweeted NAACP President Cornell William Brooks on Thursday.

During the Hannity event, Trump said “stop-and-frisk” worked “incredibly well” in New York. But a 2014 New York Civil Liberties Union report found that as the number of stops increased dramatically from 2002 to 2011 during Michael Bloomberg’s tenure as mayor, the number of guns recovered, shooting victims and murders only “changed modestly.”

In an interview on “Fox and Friends” on Thursday morning, Trump said that he was “really referring to Chicago with stop-and-frisk,” drawing questions about how widespread he believes the policy should be in practice.

Here in Pittsburgh later Thursday, Trump condemned violent protesters and called for national unity in the wake of the unrest in Charlotte following a deadly police shooting. But he did not directly confront concerns about systemic discriminatory policing nationwide.

“We honor and recognize the right for all Americans to peacefully assemble, protest and demonstrate, said Trump at the start of a speech on energy policy. “But there is no right to engage in violent disruption or to threaten the public safety and peace of others.”

He added that such disruption disproportionately hurts African Americans “who live in these communities where the crime is so rampant” and said that drugs are a “very, very big factor in what you’re watching on television at night.”

Sullivan reported from Washington.