O mystery of mysteries, the door to all wonders----the Democratic Party has failed to act progressively again. Why not assume that Democratic elected officials are doing just as they please and just as they are paid to do?
The effect and presumable goal of US border policy is to remove competition for favored traffickers of drugs and people, and to assure a steady supply of non-citizen labor that cannot readily defend itself.
The point, simply, is that they are trying to do the same thing that the Republicans try to do. They may be more racist or less racist or whatever–and yes, there’s plenty of racism and other prejudice in the system–but the main drivers of policy are economic and hierarchical.
To restate the above somewhat differently, elected Democrats do not as a group wish to undercut the creation and maintenance of a persistent underclass. If they did, they would also generally oppose the rest of the neoliberal and neoconservative agenda that goes to create this. They would not occupy themselves disrupting and destroying Honduras,. Ukraine, Libya, Syria, Iraq, Palestine, Yemen, Pakistan, and so forth.
Of course, the same argument applies to Republicans. But they only have Republican voters to satisfy, so the rhetoric is different.