In 2021, President Biden ordered the federal government to stop using private prisons. However, he left a huge exception in that executive order - ICE detention facilities.

As of July 2023, ICE detains on average 30,003 people each day. This is a significant increase from the start of the Biden administration in January 2021, when ICE held an average of 15,444 people in detention each day.
... Under the Trump administration, 81 percent of people detained each day in January 2020 were held in facilities owned or operated by private prison corporations.
In the last two years, however, this number has markedly increased: as of July 2023, 90.8 percent of people detained in ICE custody each day are held in detention facilities owned or operated by private prison corporations.

Meanwhile, this has turned in massive profits for those huge corporations.

In 2022, the GEO Group made $1.05 billion in revenue from ICE contracts alone, or 43.9 percent of its total revenue ($2.4 billion). This includes 17 percent ($408 million) on programs involving electronic monitoring of immigrants.

CoreCivic similarly made $552.2 million in revenue from ICE detention contracts in 2022, representing 30 percent of its total revenue.

Despite calls from advocates to decrease funding for ICE detention, Congress appropriated $2.9 billion dollars to hold 34,000 people in ICE detention each day for FY 2023.

It isn't all about immigration. There is also the political backlash from the George Floyd protests and the "defund the police" movement that never actually defunded any police.

As states across the country adopt harsh new sentencing laws, private prison companies are celebrating, telling investors that they soon expect more people in their prisons — and even higher profits.

From Mississippi to California, many states have taken a decided “tough on crime” tack over the past two years in a strengthening backlash to criminal justice reform efforts in the wake of George Floyd’s murder in 2020. This year, Louisiana passed a package of harsh sentencing laws that will keep some people in prison for years longer. A new parole board in Mississippi is keeping people in prison for longer terms by denying early release. In March, Washington, DC, enacted a sweeping anti-crime package.

If Trump wins things won't get any better. Private prison behemoth GEO Group was the first corporation to max out legal contributions to the Trump campaign. This is different from 2016, when they were so eager to donate to the Trump campaign that they simply ignored the law.