Dean Obeidallah, a former attorney, is the host of SiriusXM radio's daily program "The Dean Obeidallah Show" and a columnist for The Daily Beast. Follow him @DeanObeidallah. The opinions expressed in this commentary are his own. View more opinion articles on CNN.

(CNN) President Trump has shut down the government over his failure to obtain funding for a wall across America's border with Mexico. He says it's about "border security," but the reality is far more disturbing.

Trump's wall is "deeply rooted in xenophobia," Rep.-elect Ilhan Omar, D-Minnesota, explained Thursday on my SiriusXM radio show. Omar, who will make history as both the first Somali refugee and the first Muslim-American female to wear a hijab in Congress, added, "there are folks on the right, political pundits on TV shows talking about how immigrants make this country dirty and poor and more dangerous." (She was referring to recent inflammatory comments about immigrants by Fox News' Tucker Carlson.)

Omar is correct. Trump's wall is about an irrational fear of outsiders -- but it's about more than that, too. Trump's wall is designed to address a key concern of his base: the browning of America. Bluntly, Trump's wall, if built, will likely be the largest and most expensive monument ever constructed to try and ensure the demographic supremacy of white America.

True, a massive wall that climbs 32 feet in the air, as Trump has discussed, and spans thousands of miles could provide some degree of border security. But then again, so would stationing US troops -- in locked arms -- across the border, or building a massive "Game of Thrones"-type ice wall. The question is what is the most effective in achieving that goal -- especially since Trump wants us to pay for it after he failed to get Mexico to bear the cost, as he had previously promised.

This past week, Republican Rep. Will Hurd from Texas, a former CIA agent, slammed the "fallacy that a wall equals border security." He explained, "I have more border (in my district) than any other member of Congress, 820 miles," and added that we can use available technology to keep us far safer than a wall. Hurd closed with a key point: "Building a wall from sea to shining sea is the most expensive and least effective way to do border security."

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