Thirty-two Democrats in the Republican controlled Senate are sponsoring the Keep Families Together Act, which imposes a “prohibition on separation” of such immigrant families.
The bill is a long shot. No Republicans are sponsoring the legislation, and congressional leaders have given no indication they will hold votes on the bill.
But it puts President Donald Trump on notice that there is deep opposition to his “zero tolerance” policy, instituted last month, aimed at detering the thousands of families crossing the border monthly and asking for asylum.
The move has sparked domestic and international criticism, including from the United Nations which demanded a halt to what it called a serious violation of children’s rights.
“The Statue of Liberty under the Trump policy is not carrying a torch, it’s carrying a pair of handcuffs,” Senator Jeff Merkley told reporters.
According to Senator Dianne Feinstein, US Customs and Border Protection informed her that 658 children were taken from 638 parents during a 14-day period in May — an average of 47 children each day.
“This is not the United States that we know and we’re here to try to put a stop to it,” said Feinstein, the bill’s chief sponsor.
Trump has blamed Democrats for passing “bad legislation” and then failing to change the border security laws.
Democrats have countered that no law requires the government to separate children from their parents.
“Let’s call this what it is. This is a human rights abuse that is being committed by the United States,” Senator Kamala Harris said in a stinging rebuke.
The bill states that a US agency may not remove a child from a parent “solely for the policy goal of deterring individuals from migrating to the United States or for the policy goal of promoting compliance with civil immigration laws.”
Trump has made his opposition to immigration a focal point of his presidency.
His demand for building a border wall was a constant campaign theme, and he has referred to some immigrants, particularly gang members, as “animals.”
He scrapped an Obama-era program that gives legal protections to hundreds of thousands of immigrants who were illegally brought in as children, although courts have blocked their deportation.
In recent weeks Trump has hardened his message, with Attorney General Jeff Sessions insisting that illegal immigrants will be prosecuted.
“If people do not want to be separated from their children, then they should not bring them with them,” Sessions said early this month.