Republican presidential nominee Donald Trump unveiled a 10-part immigration policy plan during a speech in Phoenix on Aug. 31 after meeting with Mexican President Enrique Peña Nieto earlier in the day. (The Washington Post)

With his emphatic speech Wednesday, Donald Trump made clear that there will be no “pivot” or “softening” from him on immigration; indeed, if anything, he is now suggesting even harsher policies than he did during the primaries. One of those ideas in particular offers a window into both Trump’s ignorance about immigrants and the fears on which he tries so hard to play. Here’s part of what he said, taken from two points in the speech:

We also have to be honest about the fact that not everyone who seeks to join our country will be able to successfully assimilate. Sometimes it’s just not going to work out. It’s our right, as a sovereign nation, to chose immigrants that we think are the likeliest to thrive and flourish and love us. . . .

Another reform involves new screening tests for all applicants that include, and this is so important, especially if you get the right people. And we will get the right people. An ideological certification to make sure that those we are admitting to our country share our values and love our people.

If you think for a moment about what an “ideological certification” test would involve, you quickly realize how ludicrous the idea is (not to mention the fact that if it was testing respect for American values such freedom of the press and religion, I’m pretty sure Trump himself would fail). But the idea that the current generation of immigrants isn’t assimilating like previous ones is both widespread and completely false.

The power of that idea is undeniable, and it may be more responsible than any other factor for Trump winning his party’s nomination. The older, conservative white voters who populate the base of the Republican Party are prone to a feeling that the country they knew when they were young has slipped away from them, and it’s the fault of immigrants in general and Latino immigrants in particular. Language becomes a freighted symbol of that change: For some, hearing Spanish being spoken in their daily lives (or having to press 1 for English) can become a stand-in for everything they believe they’ve lost.

Hearing Trump bring up assimilation, I was reminded of a Republican debate back in September when Trump criticized Jeb Bush because at a town hall meeting someone asked Bush a question in Spanish and he answered in Spanish. “We have a country, where, to assimilate, you have to speak English. And I think that where he was, and the way it came out didn’t sound right to me. We have to have assimilation — to have a country, we have to have assimilation,” Trump said. “This is a country where we speak English, not Spanish.”

After Bush defended himself by essentially saying it was the polite thing to do, Marco Rubio chimed in to explain why he sometimes spoke to audiences in Spanish. It included a story about his grandfather teaching him the wonders of the free market but in his native tongue, gave a shout-out to Ronald Reagan, and closed by saying he’d keep speaking to audiences about conservative principles in whatever language they’d understand. Rubio’s comment was eloquent and moving, but you’ll remember which of those candidates won the Republican nomination.

Now here’s the simple fact: The current generation of immigrants, who come primarily from Latin America, are no less likely to assimilate than prior generations were (see here and here). Every generation of immigrants follows the same basic pattern: Those who immigrated as adults are challenged to learn English and stick mostly to their native tongues; those who came as children or who were born here to immigrant parents are likely to grow up bilingual; and by the third generation, they speak English almost exclusively and begin to lose their family’s ancestral language. That’s the way it was in my family and it’s probably the way it was in your family, too. Not only that, almost all Latinos themselves believe it’s important for immigrants to learn English, so they aren’t resisting assimilation at all.

And here’s an even more important truth: The United States does as good a job of assimilating immigrants as any country on Earth, and we always have. Among other things, it’s the reason we have had so little home-grown jihadist terrorism: Unlike in many places in Europe, the overwhelming majority of American Muslims don’t feel isolated from our society, the kind of alienation that can lead young men to decide to attempt to kill large numbers of people.

Trump won’t be storming into any Olive Garden restaurants to shout, “Why won’t these Italian immigrants assimilate?!?” That’s because after a while, the way immigrants add to and alter American culture doesn’t seem all that unsettling. And the people most responsive to this kind of nativist appeal are already firmly in Trump’s camp. In fact, even many of Trump’s own supporters aren’t as resentful and afraid of immigrants as he’d like them to be. According to this recent poll from the Pew Research Center, over two-thirds of Americans, including majorities of Republicans, think undocumented immigrants are as honest and hardworking as U.S. citizens, mostly fill jobs Americans don’t want, and are no more likely to commit crimes than citizens.

Assimilation is complicated, but it’s also inevitable, and its endpoint is usually something even the most die-hard Trumpster can embrace. Consider this viral video of a shirtless Trump supporter seemingly suffering an epic bout of roid rage, screaming at a group of protesters, “Get the f— out of here! Our country, motherf—er!” and then says, “Go f—ing cook my burrito, b—h!” before adding, “Truuump! I love Trump!” He’s plainly torn — he wants Latino immigrants to leave, yet he also wants them to stay and prepare some of their delicious food for him.

That ambivalence aside, the fear that immigrants won’t assimilate is common enough. So as a matter of policy, you can do something that addresses that fear — for instance, many comprehensive immigration reform proposals include some kind of “make them learn English” provision, requiring a test of English proficiency before undocumented immigrants can reach the end of a long path to citizenship. Even if it’s largely unnecessary in practical terms, it reassures ambivalent voters that these immigrants will truly become American.

But Trump is suggesting something different. He’s not arguing that we need to help immigrants assimilate or confirm that they have; he’s saying that we can know before someone ever sets foot in the country whether they will or not, and then let in the good ones ready to assimilate — those who can prove they “love us” — and keep out the bad ones who won’t. Even many of his own supporters probably understand how absurd that is, and it certainly isn’t going to win over the voters who currently aren’t sure who to vote for.