WASHINGTON (NewsNation) — Top Democrats have been urging President Joe Biden to abandon plans to return to what they call a “morally reprehensible and ineffective” immigration policy — the practice of detaining migrant families at the border.

“We are concerned by reports that your administration is considering a return to the ineffective and inhumane practice of detaining migrant families,” Senate Minority Leader Chuck Schumer (D-N.Y.) and 18 other Senate Democrats wrote in a letter to Biden.

The senators cited investigations and studies that revealed family detention centers pose a “high risk of harm to children and their families.”

They also argued that the policy doesn’t actually deter migrants.

Biden undid this policy when he became president, promising a more humane approach. Detaining families dates back not just to former President Donald Trump, but also to the Obama administration and even back to the Bush administration.

So, what is the current U.S. policy for handling migrant families?

Right now, families are released into the U.S. with ankle bracelets to monitor them while waiting for a court hearing. They also have mandated check-ins.

And what else is the Biden administration doing to address the crisis at the border?

Biden has announced a number of new immigration policies lately, preparing for the end of Title 42, which is expected to lead to a spike in border crossings.

One provision requires migrants to try to seek asylum in countries they travel through before reaching the U.S., and the president just announced a deal with Canada to shut down a loophole that let asylum seekers cross through the northern border.

Senate Democrats acknowledged in their letter that Congress isn’t helping the president manage this influx of migrants at the border as it fails to act on immigration reform.

NewsNation writer Devan Markham contributed to this report.