SAN ANTONIO (CN) – Democratic presidential hopeful Julian Castro grabbed hold Tuesday of the uncertainty over President Donald Trump’s threat to shut down the U.S.-Mexico border with his own plan to fix the nation’s immigration system, calling for a pathway to citizenship for undocumented immigrants and an end to laws established under Republican presidencies.

Democratic presidential candidate Julian Castro speaks during the We the People Membership Summit in Washington on Monday. (AP Photo/Jose Luis Magana)

The former Obama cabinet official and San Antonio mayor’s first major campaign policy rollout includes a proposal to reverse the Trump administration’s Muslim ban and a George W. Bush-era practice that charges border crossers with criminal violations rather than civil ones.

“This shift to criminalize immigration is at the core of many of this administration’s most egregious immigration policies – from family separation to indiscriminate ICE raids to targeting asylum seekers,” Castro, the grandson of a Mexican immigrant, wrote in a Medium.com post announcing the plan.

“It also underlies some of this administration’s most damaging rhetoric that vilifies immigrants and families,” he added.

The sweeping plan reflects Castro’s intent to seize on the nation’s growing immigration debate as federal officials struggle to keep up with the record number of border crossings topping a 13-year high. More than 76,000 undocumented immigrants crossed the southern border in March, according to U.S. Customs and Border Protection.

The strain on facilities in El Paso led to federal agents placing asylum seekers, mostly families with young children from Central America, behind a razor wire fence under the international bridge. By Sunday morning, agents had cleared the area and began relocating the influx of undocumented immigrants to other processing centers.

The Paso del Norte International Bridge in El Paso, Texas. (CNS Photo/Erik De La Garza)

In Castro’s hometown of San Antonio, local charities and city officials are overwhelmed by the mass release of hundreds of immigrant families by federal officials over the weekend. The city set up a pop-up immigration resource center across the street from Greyhound’s downtown bus station to help displaced families with food and shelter.

Since announcing his candidacy for president on Jan. 12, Castro – the only Latino in the crowded field of 2020 candidates who has struggled to gain traction in early polls – has woven the story of his own family’s journey into the United States as part of his political narrative.

He has repeatedly hit Trump for what he called “a failure of leadership” and blamed his “misguided policies” for a backlog at the southern border.

“One of my strongest memories of my grandmother is the way she would tell my twin brother, Joaquin, and me about how she came to this country as a child after being separated from her dying mother,” Castro recounted in his blog post. “Even as a seventy-year-old woman, when she recounted those moments, she would cry like the seven-year-old girl she was when it happened, sobbing that she never got to say goodbye. I see her image in the children at our borders today.”

Trump has yet to decide whether he will indeed close the U.S.-Mexico border, but he seemingly dialed back his tone against Mexico on Tuesday, tweeting: “After many years (decades), Mexico is apprehending large numbers of people at their Southern Border, mostly from Guatemala, Honduras and El Salvador. They have ALL been taking U.S. money for years, and doing ABSOLUTELY NOTHING for us, just like the Democrats in Congress!”

Neil Bradley, executive vice president and chief policy officer for the U.S. Chamber of Commerce, warned that even threatening to close the border “creates a degree of economic uncertainty.”

“Closing the U.S.-Mexico border would inflict severe economic harm on American families, workers, farmers, and manufacturers across the United States,” Bradley said in statement. “U.S. trade with Mexico exceeds $1.7 billion daily, and nearly half a million people legally cross the southern border every day as workers, students, shoppers, and tourists.”

Castro’s immigration plan also proposes to allow all deported veterans who honorably served the country to return to the United States, and to end the practice of deporting such veterans. In addition, he has called for strengthening labor protections for skilled and unskilled guest workers and eliminating the for-profit immigration detention and prison industry.

Castro also said he would end “wasteful spending on a pointless wall, and cuts to the refugee program.”

“It’s time that we recognize that protecting our borders and treating immigrants with compassion are not mutually exclusive. I’m proud to unveil an immigration policy that re-integrates those collective values in our immigration system,” he said.