The opinions expressed by columnists are their own and do not necessarily represent the views of Townhall.com.

What if diversity isn't our strength?

Sen. Lindsey Graham says he scolded the president for saying something scatological about certain countries and their emigrants. "Diversity has always been our strength," Graham allegedly said. By my very rough count, this makes Graham the bazillionth person to proclaim some variant of "diversity is strength."

But is it true? I think the only close to right answer is, "It depends." Specifically, it depends on which (often cliched) analogy you want to hang your argument on. Diverse stock portfolios are more resilient. Diverse diets are healthier. But that doesn't mean picking bad stocks will make you richer, nor that eating spoiled foods is good for you.

I once heard the Rev. Jesse Jackson explain that racial integration of the NBA made it stronger and better. He was right. But would gender integration of the NBA have the same effect? Would diversifying professional basketball by height? Probably not.

In other words, all of these analogies can only take you so far. Thomas Sowell once said, "The next time some academics tell you how important diversity is, ask how many Republicans there are in their sociology department."

There's a growing body of evidence that even if diversity once made America stronger, it may not be doing so anymore, at least in the short and medium term. Robert Putnam, a liberal sociologist at Harvard, found that increased diversity corrodes civil society by eroding shared values, customs and institutions. People tend to "hunker down" and retreat from civil society.

I think the real culprit here isn't immigration or diversity in general, but the rising stigma against assimilation. Particularly on college campuses, but also in large swaths of mainstream journalism and increasingly in the louder corners of the fever-swamp right, the idea that people of all backgrounds should be encouraged to embrace a single conception of "Americanism" is increasingly taboo. Anyone of any race or national origin can be an American, but it requires effort and desire from both the individual and the larger society. There's a shortage of both these days.

But while traditional notions of assimilation are increasingly heretical, there is a kind of anti-assimilation assimilation movement afoot. It insists that we must "celebrate our differences" and make them the essence of our identity. The University of California officially considers terms like "melting pot" offensive and "triggering." But no one would confuse the UC system as a hotbed of free and independent thought. What is expected is assimilation into an ideological worldview all its own, one that simply asserts without proof that one kind of diversity makes us stronger.

So far, all of this should be familiar to anyone who has followed the debates over immigration and assimilation. Liberals, broadly speaking, assert that diversity makes us stronger. Conservatives, broadly speaking, respond with skepticism or emphasize a different kind of diversity.

What gets less attention, however, is the premise that "strength" is an indisputably overriding priority or ideal.

Strength has always struck me as a strange ideal for a democracy. Strength, like other fetishized ideals such as "unity," is wholly amoral. Even "diversity makes us richer" has more moral content than "diversity makes us stronger." Stronger to do what, exactly?

This has been one of my core objections to Donald Trump's rhetoric. He constantly extolls strength, at home and abroad. He praised the Chinese government for showing strength at Tiananmen Square. He admires Vladimir Putin's strong leadership. On the campaign trail, he upended the traditional conservative critique of big government by decrying the "weakness" of America's political leaders and institutions.

Strength, it seems to me, is a top priority of every nationalist creed. It fits more uncomfortably within American notions of patriotism. If you read the Federalist Papers, you'll learn that among the top priorities of the founders was to ensure that the government, particularly any branch of government, not be too powerful. The Bill of Rights is all about constraining the power of government. The Constitution never once mentions the words "strength" or "strong." Neither does the Declaration of Independence. But both documents include a great deal about freedom and liberty.

Of course, I don't want America to be weaker, depending on how you define weakness. But maybe the overriding problem with the debate, on both sides, is the assumption that strength is its own reward?