ALBUQUERQUE, N.M. (AP) – During the primaries, Donald Trump threw red-meat rhetoric to supporters, pledging to build a wall on the Mexico border and to ban Muslim immigrants. He even told at least one crowd that he wanted to punch a demonstrator who disrupted an event.
Now that he's the GOP presidential nominee, who needs to appeal to the whole country, some observers say he's turning to tried-and-true code words to gin up racial animosity and fear among America's white voters.
Trump "didn't get on stage and issue a bunch of racial epithets," said Emory University political scientist Andra Gillespie, who watched his acceptance speech at the Republican National Convention. "We didn't hear the N-word, and we didn't hear other words that may offend many people. But just because he didn't use racial slurs doesn't mean he didn't frame issues in a way that people in racial and ethnic groups find problematic."
Ian Haney Lopez, author of "Dog Whistle Politics: How Coded Racial Appeals Have Reinvented Racism and Wrecked the Middle Class," went further, saying Trump's speech surpassed even the coded racial language of Richard Nixon in 1968.
In addition to appealing to whites' racial anxieties about crime, the celebrity businessman added immigrants to the mix and said refugee families with unknown backgrounds threaten to transform the nation unless drastic measures are taken, Lopez said.
"This was a speech that said essentially that the barbarians are at the gate," he said.
Samuel LeDoux, a Republican delegate from New Mexico who is Hispanic, said he didn't hear racial overtones in Trump's speech.
"I think people are reading too much into it," said LeDoux, 24, who agrees with Trump's call to reduce illegal immigration because it is affecting wages. "He comes from New York, a very diverse city."
When asked Friday for a comment, a Trump spokesman said the campaign was focused on a deadly shooting in Munich, Germany, and would respond later.
Trump has been criticized for his racial language since the beginning of his campaign, which started with his declaration that the Mexican government is "forcing their most unwanted people into the United States," including drug dealers and rapists.
"In all these cumulative ways, you start to get the strong sense that when he says 'we and us,' he's only talking about whites in the United States," said Tomas Summers Sandoval, a history and Latino studies professor at Pomona College, in Claremont, California.
Some have pointed out that Trump's slogan "America First" was also the slogan of the America First Committee, an isolationist, anti-Semitic group whose primary goal was to keep the United States from joining Britain in the fight against Nazi Germany. The group opposed the acceptance of shiploads of Jewish refugees fleeing Nazi persecution.
As he sewed up the nomination, Trump declared himself the "law-and-order" candidate. In Cleveland, he repeated the idea.
"I have a message to every last person threatening the peace on our streets and the safety of our police. When I take the oath of office next year, I will restore law and order to our country," he said. "In this race for the White House, I am the law and order candidate!" Trump exclaimed.
When they hear that phrase, anxious white voters fill in any picture they want in their minds, imagining cutting crime or pushing back against social causes like the women's movement, said Michael Flamm, Ohio Wesleyan University history professor and author of "In the Heat of the Summer: The New York Riots of 1964 and the War on Crime."
But for some, there's a clear racial element, he said.
"For some people, law and order was a way to express a racially coded message, and some white voters responded to law and order because they believe it supported their anti-civil rights, anti-racial justice beliefs," Flamm said.
Politicians of both parties have long used coded language to stoke enthusiasm and fear among American voters.
The late political operative Lee Atwater, manager of George H.W. Bush's 1988 presidential campaign and a South Carolina native, was open about the evolution of racial code words in political campaigns.
In the early 1950s, racial slurs like the n-word were common. But by 1968, politicians had abandoned those terms, knowing they could backfire. So instead "you say stuff like forced busing, states' rights and all that stuff," Atwater said in an interview for the book "Southern Politics in the 1990s."
Faced with racial riots, anti-war protests and rising Vietnam War casualties, Nixon played off the nation's deep divisions in 1968 by calling for law and order and promising to speak for the "silent majority." He adopted a "Southern strategy" that emphasized appealing to whites' disaffection with liberal Democratic civil rights policies but rejecting overtly racist stances.
Critics argued that Nixon's "silent majority" was merely a coded way of saying middle-class whites. In television commercials, the campaign showed images of bloody protests, burning cities and police in riot gear. Each Nixon commercial ended with the words, "This time vote like your whole world depended on it."
Much of the coded language remained during Nixon's 1972 re-election bid.
"The subliminal appeal to the anti-black voter was always in Nixon's statements and speeches on schools and housing," Nixon's top domestic aide, John Ehrlichman, wrote in his 1981 book "Witness to Power."
President Ronald Reagan referred to "welfare queens," a term many saw as coded language for black women. He also made an appearance calling for "states' rights" at the Neshoba County Fair in Philadelphia, Mississippi, where three young civil rights workers were slain in 1964.
The 1988 contest between then-Vice President George H.W. Bush and Massachusetts Gov. Michael Dukakis included the infamous Willie Horton commercial, which featured a black murder suspect who raped a white woman during a weekend furlough program that Dukakis had at one time supported.
More recently, Hillary Clinton has been criticized for her use of the term "superpredator" in the 1990s to refer to a supposed wave of lawless teenagers that never emerged. Critics have complained that the word targeted black and Hispanic youth and led to overzealous prosecution and incarceration.