Many of the nonprofits, corporations and religious groups watching over migrant children detained at the southwest border have been in this business for years — and they have a history of donating millions of dollars to Democrats and Republicans alike.

Now, as new federal policies greatly expand the number of migrants held in detention, it is also becoming clear that some of the players in this billion-dollar industry have strong ties to the Trump administration.

President Donald Trump's defense secretary sat on the board of one of the groups. Trump's inauguration fund collected $500,000 from two private prison companies housing detained migrant families. And some of the contractors employ prominent Republican lobbyists with ties to Trump and his administration.

There is no indication that political favors or influence motivated any of the contracts, and the service providers have no apparent ties to the agency awarding most of the contracts, the Department of Health and Human Services. Many of the groups had federal contracts to work with migrant children long before Trump took office.

Yet the administration's new focus on ending the practice of "catch and release" has meant that the business of housing and caring for migrant children is booming. A review of regulatory filings, campaign donations and lobbying records reveals a number of links between people in Trump's orbit and the groups poised to benefit from his immigration policies.

Migrant youths detained at the border are housed at more than 100 government-contracted shelters, detention centers and other facilities across the country.

The groups operating them have hauled in more than $1 billion in contracts in recent years to house, transport and watch over migrant children in federal custody. Although some of the contractors have spoken out against the separation of migrant families, most have made few public remarks and have instead quietly defended themselves, saying they housed and cared for unauthorized youths during the Obama administration without controversy, and remain dedicated to protecting vulnerable children.