KANSAS CITY, Mo.  — Donald Trump’s aggressive rhetoric on illegal immigration has obscured a potentially historic policy shift — the Republican presidential nominee is the first major party candidate in modern memory to propose limiting legal immigration.

In his speech on immigration Wednesday night, Trump capped a list of steps to combat illegal immigration, with a final pledge to completely revamp the country’s legal immigration system in order to lessen the number of people allowed into the United States. “We will reform legal immigration to serve the best interests of America and its workers, the forgotten people,” Trump said. “Workers. We’re going to take care of our workers.”

Trump talked about limiting immigration to its historic norms. The share of foreign-born people in the United States — 13 percent of the population — is at its highest level since 1920. By making the case in a nationally televised address that immigration overall has to be limited, Trump has embraced the ideals of a small group of activists who, for decades, have sought to sharply reduce all forms of migration to the United States.

“It’s a big change,” said one of those activists, Roy Beck, president of Numbers USA, who argued that Trump can espouse ideas that previous politicians, dependent on campaign contributions from business, cannot. “The politicians who are major speakers on this have always focused on rule of law.”

Since the 1990s, politicians who have taken a tough stance on immigration have usually come out against amnesty for anyone living in the country illegally, but spoke favorably of legal immigration. Many business groups that traditionally support the GOP seek higher levels of legal immigration. Advocates say the push underscores how necessary migration is for the economy, while critics contend it pushes wages down.

“For Trump, it’s ‘I’m all against immigration, legal or otherwise, full stop’ — which is a massive departure for the Republican party,” said Ali Noorani of the National Immigration Forum Action Fund. “He wants to turn around the demographic trends of the country and return the United States to a majority white country.”

It’s also a stark contrast with Democrat Hillary Clinton, who wants to expand President Barack Obama’s order deferring deportation for many in the country illegally, and supports measures that would expand legal immigration.

The demographic transformation by legal immigration dwarfs that resulting from illegal entry. The U.S. Census estimates that whites will be a minority in about 30 years, with the number of immigrants on the rise.

The upswing in immigration started in 1965 with the removal of racially based immigration quotas that favored immigration from European countries over the rest of the world.