WASHINGTON — Democrats expanded their campaign Sunday to spotlight the Trump administration’s forced separation of migrant children from their families at the U.S. border, trying to compel a change of policy and gain political advantage five months before midterm elections.

Against a notable silence on the part of many Republicans who usually defend President Trump, Democratic lawmakers fanned out across the country, visiting a detention center outside New York City and heading to Texas to inspect facilities where children have been detained.

In McAllen, Texas, where several Democratic lawmakers toured a facility, Rep. Vicente Gonzalez of Texas estimated that he saw about 100 children younger than 6.

“It was orderly, but it was far from what I would call humane,” he said.

Seven Democratic members of Congress spent Sunday morning at the Elizabeth Contract Detention Facility in New Jersey, waiting nearly 90 minutes to view the facilities and visit five detained immigrants.

“This is unfair and unconstitutional,” said Rep. Adriano Espaillat, D-N.Y.

Trump has falsely blamed the separations on a law he said was written by Democrats. But the separations instead largely stem from a “zero-tolerance” policy announced with fanfare last month by Attorney General Jeff Sessions. The White House also has interpreted a 1997 legal agreement and a 2008 bipartisan human trafficking bill as requiring the separation of families – a posture not taken by the George W. Bush or Obama administrations.

Trump remained silent on the issue Sunday. In a radio address on Saturday, however, he brought up the topic of “unaccompanied alien minors” in a broadside against Democrats who he said had created “glaring loopholes” that let in young members of the MS-13 international gang.

“Democrats in Congress have opposed every measure that would close these immigration loopholes and bring this slaughter to an end,” he said after recounting a litany of crimes he said were committed by immigrants here illegally. He said he was defending “every American child.”

White House officials and allies on Sunday dug in and defended the policy, insisting, as Trump has, that the administration was following existing immigration law.

“I don’t think you have to justify it,” former senior White House adviser Stephen K. Bannon told ABC’s “This Week.” “We have a crisis on the southern border.”

“They are criminals when they come across illegally,” Bannon said.

Senior White House adviser Kellyanne Conway answered critics’ complaints by telling members of Congress to change immigration measures on the books.

“If they don’t like that law, they should change it,” Conway said on NBC’s “Meet the Press.”

The divisions between the White House and its critics on both sides of the aisle opened a signal week when it comes to the nation’s immigration policies. President Trump is due to speak Tuesday to Republican members of Congress on the issue, which has confounded both ends of Pennsylvania Avenue for a generation.

Republicans are considering two measures, both of which give the president much of what he has demanded, including billions for construction of a border wall, sharp curbs on legal immigration and other security mechanisms. But neither a conservative proposal – nor a more moderate one that would allow families to be detained together – was guaranteed enough support among party members who have long been split on how to deal with immigrants in the country or seeking entry.

Democrats, actively denouncing the zero-tolerance policy, have remained united against the Republican measures but are pushing a bill by Sen. Dianne Feinstein of California to immediately block family separations. No Republican has publicly supported that option.

After equivocating Friday about which of the two Republican immigration measures he would support – and shaking up Republican Party members seeking signs from the White House – Trump later said he would back either one.

White House officials have said the president is betting that by continuing to separate families, he will gain political leverage in negotiations with Congress over a new immigration bill and cause a drop in the number of immigrants seeking entry.

A sign of the difficult balance over which all sides were tussling came Sunday from a statement released by a spokeswoman for first lady Melania Trump.

“Mrs. Trump hates to see children separated from their families and hopes both sides of the aisle can finally come together to achieve successful immigration reform,” it said. “She believes we need to be a country that follows all laws, but also a country that governs with heart.”

U.S. officials have said that the number of families who could be broken up might double and that the number of children who’ve already been taken from their parents – 2,000 over a six-week period from April to May – may be higher than what the administration has reported.

Already, the policy has sparked a public relations crisis as the administration has been confronted with photos of young, bewildered children being separated from their parents at the border – a difficult scenario under any circumstances but one that landed with a particular poignancy on Father’s Day weekend.

Notable Republican allies, such as evangelist Franklin Graham, who has defended Trump at every turn of his presidency, have broken with the administration in recent days. Graham called the family separations “disgraceful.”

Other religious leaders and a host of child welfare organizations have fiercely criticized it, contending that it will harm the children throughout their lifetimes.

Democratic leaders worked to maximize negative publicity over the weekend, hoping to prompt a national push against the policy that would also play to their benefit in November.

Appearing on “Meet the Press,” Rep. Adam Schiff, D-Calif., likened the president’s demands to extortion.

“What the administration is doing is, they’re using the grief, the tears, the pain of these kids as mortar to build their wall,” Schiff said. “It’s an effort to extort a bill to their liking in the Congress.”

Rep. Beto O’Rourke, Texas, was one of several Democratic lawmakers who headed to the border or other detention centers this weekend to mark Father’s Day with a public demonstration. He said on CNN’s “State of the Union” that House Democrats would introduce legislation this week to ban the practice.