Republicans in Congress are at risk of being torn apart over the issue of immigration. While many members from purple districts see settling the Dreamer issue as vital for their re-elections, others from more solidly red states want to restrict new legal immigration and deport anyone living here illegally.

Tribalism has always been one of the strongest of human genetic traits. In a more dangerous past, men felt safest among their own, first family, then clan. Only capitalism and its resultant prosperity brought about the unification of disparate national minorities into modern European nations. Recently in southern France I was surprised to learn that only under Napoleon was a single French dialect finally imposed upon the whole nation. Before Napoleon’s conscription of large armies, Frenchmen from different parts of the country could scarcely understand each other. People are naturally conflicted over those who are different from them—think today of Northern Ireland, or the Belgian Flemish and Walloons, or Catalan separatists in Spain.

America is unique because it transcended this tribalism to become a multi-ethnic and multicultural nation. America is not, like European countries, based on ethnicity. It’s often forgotten that we were founded when Europe’s religious wars were still a fresh memory, and many of our ancestors came here to escape them. Polish writer Frank Glodek explains that even at the time of our founding we were a multi-religious and multicultural nation by the standards of the time. In Europe, Catholics and Protestants had massacred each other by the millions—similar to what many Muslims are doing to each other today.

That brings us back to immigration, which could be a tremendous, divisive threat to Republicans, easily costing them control of Congress this fall. Daniel Henninger explains in the Wall Street Journal how Trump won Florida with only 1.2 percent of the votes cast and Texas with 52.4 percent. Both have fast-growing Hispanic populations. If those two states were to turn Democratic, it would be the end of Republican legislative dominance for many years, as has already happened in California.

Another Journal article by David Leonhardt reports that only 21 percent of Hispanics bothered to vote in the 2014 midterm elections. The census, meanwhile, reports that 23 percent of all students in America are Hispanic, and 23 percent of public school students have at least one immigrant parent. Yet Republican leadership risks losing these potential future voters. Instead, at conservatives’ recent CPAC gathering, leadership was pandering to anti-immigrant nationalism. That might appeal to older white voters, who often live in states with the fewest immigrants, but not to Millennials. A recent Weekly Standard article, “Conservatives Have a Millennial Problem,” observes that among young people “roughly 8 in 10 believe immigrants have a net positive impact on society.”

As of right now, the economy is dependent upon illegal immigrants in agriculture, food service, construction, and home care. George Will recently noted that “half of agricultural workers are undocumented immigrants.” He points out that labor shortages have already shut down 30 to 60 percent of selected vegetable and fruit production. In the simplest terms, unskilled immigrants picking crops or in construction create jobs for skilled truckers, manufacturers, advertisers, financiers, etc. (There are also other growing labor shortages.)

To tackle the immigration issue, conservatives and moderates should compromise with tradeoffs. DACA (Deferred Action for Childhood Arrivals) is widely supported, according to polling. Allowing younger immigrants who have grown up in America to become citizens and letting their parents have some form of legal residency would, very importantly, take the pressure off of conservative candidates in the fall elections. It would still leave open the issue of temporary visas for agricultural workers for another time, but so be it.

We could also immediately change the law on chain migration and replace it with merit-based immigration based on skills and America’s labor needs. Even most Hispanics support this. Nearly all other nations limit relatives’ immigration to immediate family, wives, and children, and possibly parents. Relatives represent some 70 percent of all immigration to America; cutting them back would answer the arguments of those who think that we are taking in too many immigrants and need a cooling off spell to absorb those we already have. The visa lottery could also be eliminated. It brings in some 50,000 immigrants per year.

Although we generally want to prioritize educated and skilled immigrants, we should not forget that it is often the poorest who have contributed the most. Horizontal fracking of oil and gas wells, which gives America new, abundant, cheap energy, was discovered by the immigrant son of a Greek goat herder, hardly an example of the educated Norwegians Trump would prefer.

Polling shows that most Americans support a path to legal residency for most illegal immigrants. This could be done with renewable work permits, without granting them citizenship, but giving them legal status under American labor laws. This would also raise many of their wages so they don’t undercut American workers’ incomes. They will still take jobs that most Americans will not do. Most don’t care about voting; they just want legal status to work. Many would later return to their own nations once they had saved up some capital. They also don’t need to be entitled to welfare except for health care. However, we should absolutely educate their children, and we should enact strong programs of Americanization, explaining our constitutional system and how it made us prosperous.

The current furor over separating small children from their parents, mainly Central Americans, is just a foretaste of what would happen with a major expulsion of millions of illegals, many with American-born children and spouses who are citizens. Instead the current law should be changed. Mainly it allows families to claim asylum with its consequent legal procedures for verification if they come across recognized border control points but the courts are incredibly overloaded and backed up. The separations are occurring now when adult immigrants illegally cross our borders with children and are then judged as criminals per the Department of Justice’s relatively new “zero tolerance policy.” These immigrants are now being purposefully separated from parents to discourage others from trying to enter America. It’s a nasty situation and we need to fix it.

We should also want a prosperous Mexico on our border to curtail these flows, as I have written before.

Trump’s negative appeals on immigration—legal or otherwise—is stirring up racial and ethnic strife inside America. The one way our prosperity and power in the world could really be diminished is if we start fearing, denigrating, and fighting each other. Asians Americans voted in even higher percentages against Trump than Hispanics. There’s a simple reason for that: they saw themselves as the possible future targets of his chauvinism.

Director of National Intelligence Daniel Coats, a Trump appointee, recently warned that “political polarization and inflammatory rhetoric play directly into the hands of America’s very active enemies.”

Of course opponents are most concerned with assimilation. It’s not about family values—most immigrants are fairly religious and conservative, and strongly oppose abortion. The leftist undermining of traditional values is not their fault. Our undisciplined big city schools, our declining international test scores, the coarsening of our culture, Washington’s repeated war making—none of this is the fault of immigrants.

Yet writers continue to compare our problems to Europe’s Muslim immigrant influx, particularly France’s. America’s immigration is not comparable. First, we have an economy that provides hope, jobs, and opportunities for small entrepreneurship, unlike European socialist nations with their stifling taxes and labor laws. Secondly, most of our immigrants are from Hispanic nations with historic ties to American heritage and Western civilization. They can and do assimilate.

The most difficult assimilation is assumed to be that of Muslims. In 2016, the Cato Institute published a study, “Muslim Integration & Integration in the United States and Western Europe,” explaining how European labor laws create vast unemployment among immigrants and why Muslims assimilate far better in the U.S. In Germany, where there are jobs and education, there is far, far less of a terrorism threat. Germany also is not bombing or attacking Muslim nations, which can agitate second-and third-generation immigrant young males into becoming terrorists. TAC, of course, opposes these Washington wars in the Muslim world in part for that reason.

America is large and rich enough that those who want to live in traditional, culturally pure neighborhoods, mainly in the heartland, can still do it. Equally, those living in large coastal cities, immigrant and mixed, can also be comfortable in their preferred lifestyles. Most Americans will not support the brutality needed for a mass expulsion of millions of already-settled immigrants, often with American-born children. For conservatives the challenge should be to cool the inflammatory rhetoric and work towards a compromise settlement of the issues. We must deal with America’s real problems, not indulge in fantasy solutions.

As my old friend Allan Brownfeld has written, we forget easily that civilization hangs by a thread. The convulsions of the 20th century, of communism and Nazism, should be a constant reminder of what can happen from wars and economic chaos.

Mr. Utley is publisher of The American Conservative. He has written widely on third-world economics, terrorism, and foreign policy.