Round them up

1. Trump made some statements about Japanese internment last December. However, that was in the context of Muslim immigration policy, so the Japanese comparison got swamped by the Muslim issue. 

Muslims are a social mascot of the Left. By contrast, Asians tend to be ignored by the liberal establishment, when they are not positively discriminated against by the liberal establishment (i.e. college admissions). In addition, it's my impression that Asian-Americans are apt to be less political vocal, so Trump's statements about them didn't get the same buzz. 

2. Trump frequently makes statements that are denounced by both sides of the political spectrum. However, it's not enough to denounce his statements. Indeed, that can be counterproductive. The very statements that come in for denunciation are popular among his supporters, and they take this as vindication that he's the anti-Establishment candidate.

Therefore, we need to dissect some of his statements and explain what's wrong with them. In reference to Japanese internment, he said:

“I would have had to be there at the time to tell you, to give you a proper answer,” he said during a recent interview in his office in New York City. “I certainly hate the concept of it. But I would have had to be there at the time to give you a proper answer.” 

http://time.com/4140050/donald-trump-muslims-japanese-internment/

But that gets it exactly backwards. Historical distance can give us a much better perspective than public officials at the time who were reacting in the heat of the moment. 

On Morning Joe, Trump appealed to FDR's internment policy as an analogous precedent to justify his position on Muslim immigration:

https://www.youtube.com/watch?v=43s7udRBBow

i) But that simply begs the question of whether FDR overreacted. 

ii) Moreover, the analogy is vitiated by equivocation. Islam is an ideology, not an ethnicity–unlike Japanese ancestry. 

3. In fairness, Trump is not the only person to suggest the internment was justifiable, and extrapolate from that example to Muslim counterterrorism. To take a lowbrow example, there's Michelle Malkin's In Defense of Internment: The Case for 'Racial Profiling' in World War II and the War on Terror.

But among other things, that suffers from the same specious and pernicious comparison: criminal profiling isn't equivalent to racial profiling. That conflates ethnicity with ideology. To be Japanese is not an ideological identity; to be Muslim is not an ethnic identity. 

4. To take a highbrow example, you have pragmatic, authoritarian judges like Richard Posner (Not a Suicide Pact: The Constitution in a Time of National Emergency) and William Rehnquist (All the Laws but One: Civil Liberties in Wartime) who view the Bill of Rights as an accordion that expands in peacetime and contracts in wartime. But there are basic problems with that approach:

i) Isn't the whole point of having a written Bill of Rights to isolate some civil liberties from the vicissitudes of politics and current events?

ii) I reject the false dichotomy between liberty and security. A police state isn't safer for the general public. Indeed, it's dangerous to the general public. 

iii) Likewise, I reject a dragnet approach to public safety. I don't object to criminal profiling. "Racial" profiling is usually a misnomer. 

5. Apropos (4), as US citizens, Japanese-Americans were entitled to full due process rights under the Constitution. Surely the interment policy was a flagrant violation of the Fifth Amendment. Not to mention the hardship of Japanese-Americans or foreign nationals who lost their homes and businesses in a fire sale. 

6. The rationale for internment was to take precautionary measures against domestic espionage and sabotage by Japanese-Americans. But there are multiple problems with that rationale:

i) Even if that was a legitimate concern, it doesn't contravene other considerations (see above, under #4-5). 

ii) What about the disparity of treatment? If folks with Japanese surnames are suspect, what about folks with German surnames like Hans Bethe and Dwight Eisenhower, or Russian surnames like Boris Pash and Igor Sikorsky, or Italian surnames like Enrico Fermi? These, too, were hostile countries. 

iii) A continental nation like the US was in no danger of being conquered by an island nation like Japan. Japan is about 146,000 square miles while the continguous US is about 3.2 million square miles. It's not as if Japan could stage a successful invasion and occupation. 

iv) American military intelligence was dependent on Japanese-Americans to serve as interpreters and translators. In addition, Japanese-American soldiers in the 442nd Regimental Combat Team and 100th Battalion fought with utmost dedication and valor. Evidently, Trump knows nothing about the contribution that Japanese-Americans made to the US war effort. For instance:

http://encyclopedia.densho.org/Japanese_Americans_in_military_during_World_War_II/

It's absurd to have folks fighting and dying to defend your country when their relatives are summarily incarcerated in internment camps. It's absurd to think they can be trusted to furnish vital expertise in military intelligence, but can't be trusted to live and work in the civilian population.