The midterm elections proved one thing definitively: We are a deeply divided country. Though the Democrats’ victory in flipping the House of Representatives was significant, it might have been even bigger had President Donald Trump not been able to use the caravan of Central American migrants to stir fear and motivate his base. The left doesn’t get it, blaming unalloyed racism. No doubt, there was plenty of racism to point to in the president’s ads and his invocation of an “invasion,” but the truth is that the hard-line restrictionists who were motivated by Trump’s rhetoric about the caravan aren’t all racists.

I am an unabashed advocate for immigrants and immigration reform that would make it easier to come to the United States. That has been my position for more than 30 years. But I also understand the anxieties that large-scale immigration provokes among many Americans.

Some fear competition from immigrants, who will often work for less (which is what a free market allows and capitalism encourages, to the benefit of the larger economy). Others worry that immigrants will change the culture, feeling pressure to accommodate new languages and customs rather than seeing newcomers being expected to adapt to the common culture. And no amount of evidence that immigrants of this generation and their children are doing what every group before them has done — learning English, improving their educational and economic statuses, and intermarrying with those outside their own group — can convince these skeptics when they have to “push 1 for English” on the phone or show up to vote and see ballots printed in Spanish.

Until Democrats recognize that the multiculturalism they have pushed for a generation actually hurts their case for remaining a country that welcomes large numbers of immigrants, they will have a hard time broadening their appeal to blue-collar and rural Trump voters.

President Trump may have used naked lies to portray the caravan as being filled with gang members and even potential terrorists from the Middle East, but the response (including mine) that it’s composed mostly of women and children fleeing violence and men seeking jobs didn’t address the concerns provoking many voters. What these voters see is a large group of people who would strain the resources of their communities. Those women with young children may be fleeing violence and hoping to work in America to provide a better life for their children, but if they were to manage to gain entry (legally as asylees or illegally as undocumented immigrants), their children would enter school not speaking English and entitled to emergency health care.

Sure, their numbers are small in the scheme of things — at most, several hundred will make it to the border — but Trump’s supporters see them as an endless chain about to make demands on their communities. Over time, even these impoverished migrants would move up the economic ladder, and their children would be even likelier to achieve the American dream. But the older white voters who see the caravan members as a threat probably won’t even be around to assess that success.

In 1994, in the first wave of anti-immigrant ballot initiatives that swept several states, Proposition 187 won in liberal California. The turning point in that campaign came when 70,000 Latinos opposing the measure marched through the streets of Los Angeles, many of them carrying Mexican and other foreign flags. In 2014, some immigration reformers thought they were on the verge of a modest deal that might make it through Congress, but a surge of some 60,000 unaccompanied minors stopped discussions in their tracks.

So, too, as migrants headed north this week on foot, by bus and atop trains, many voters saw not opportunity seekers or a humanitarian crisis but foreign-born people demanding entry.

And the incessant media coverage, even that meant to be sympathetic, didn’t help. For those who see a threat, it made the danger seem imminent. Even for those who don’t fear the caravan, the impoverished condition of the migrants makes clear that they would impose burdens, if only temporary.

President Trump rode anti-immigrant animus to victory in 2016 and used it to mobilize his voters Tuesday. Those of us who believe that Trump does not deserve a second term must figure out how to keep him from beating this drum in 2020. We can start by doing whatever we can to discourage large groups of people from showing up at the border without permission to enter. Americans don’t like a mob, especially one making demands.

Editor’s note: Linda Chavez is chair of the Center for Equal Opportunity and a senior fellow at the Niskanen Center. To find out more about Linda Chavez, visit the Creators Syndicate website at www.creators.com.