A group of Central Americans on a slow-motion trek north through Mexico toward the United States exposes deep flaws in America’s political asylum system, a former immigration law judge said.

Andrew “Art” Arthur, who now is a senior fellow in law and policy at the Washington-based Center for Immigration Studies (CIS), said on “The Laura Ingraham Show” on Monday morning that the asylum treaty to which both Mexico and the United States are parties requires persecuted people to seek asylum in the first safe country.

When some 1,200 Central Americans finally reach America, Arthur said, President Donald Trump needs to take a strong stand.

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“Unfortunately, it is a flaw in American immigration law today that we don’t consider the fact the people have passed through other asylum-granting countries, including Panama, Costa Rico and Mexico on their way to the United States,” he told guest host Paul Viollis. “And we probably need to make a fix to that.”

Trump tore into Mexico on Twitter over the weekend, tying the issue to the North American Free Trade Agreement (NAFTA).

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“Mexico is making a fortune on NAFTA … They have very strong border laws — ours are pathetic,” he tweeted. “With all of the money they make from the U.S., hopefully they will stop people from coming through their country and into ours, at least until Congress changes our immigration laws!”

Mexico, Arthur said, simply lets asylum seekers pass through its country on their way to the U.S. border.

“That’s not being a good neighbor. That’s actually doing exactly the opposite,” he said.

Arthur said the federal government should start detaining asylum seekers, while immigration law judges make determinations about whether their claims of persecution are valid.

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Arthur said from his experience, fraud is common. But he added that no one knows just how common it is.

Mexico is making a fortune on NAFTA…They have very strong border laws – ours are pathetic. With all of the money they make from the U.S., hopefully they will stop people from coming through their country and into ours, at least until Congress changes our immigration laws! — Donald J. Trump (@realDonaldTrump) April 2, 2018

He said U.S. Citizenship and Immigration Services (USCIS) officials several years ago began studying the issue and turned up many cases of fraudulent asylum claims.

“But unfortunately, that study got shut down and was never completed,” he said. “The United States government needs to go back forensically, look at individuals who have been granted asylum and go back to the home countries, see whether the claims are true or not.”

Arthur said that when he worked as an immigration judge, he found inconsistencies in a majority of cases.

“Unfortunately, it’s very easy to make a fraudulent asylum claim … One, it’s in violation of our law, but two, there are good claims out there,” he said. “But those people can’t get their claims heard in a timely manner. They can’t protect their families back home by bringing them to the United States, because these bad claims, these fraudulent claims, clog the system.”

Arthur covered a wide range of topics. He said it is frustrating that public officials enforce hard-core “sanctuary” policies, but he added that making alien-harboring cases against them — as some have suggested — would be difficult to make stick.

Arthur also criticized California Gov. Jerry Brown, who granted pardons last week to five immigrants facing possible deportation, including a man convicted of kidnapping, robbery and firearm use during the commission of a felony.

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Arthur said immigration courts accept such pardons. Other states have taken similar steps. For instance, Arthur noted, state’s attorneys in Maryland have instructed prosecutors not to file the most serious charges against some legal immigrants in order to avoid triggering deportation proceedings.

Those crimes include driving under the influence of alcohol, domestic abuse, and child molestation. Arthur said the three have something in common — perpetrators repeat their offenses in most cases.

“Gov. Brown has subverted that system. It’s his right, but I don’t think it is right.”

“The fact is that if do it once, you’ve probably done it before, and unfortunately, you’re likely to do it again,” he said. “Those are the sorts of individuals that the immigration laws are meant to keep out of the United States. But unfortunately, by taking this action, Gov. Brown has subverted that system. It’s his right, but I don’t think it is right.”

PoliZette senior writer Brendan Kirby can be reached at [email protected]. Follow him on Twitter.