As controversy grows over his administration's treatment of children separated from undocumented immigrant parents , Trump is seeking a political opening to damage his opponents and solidify his own support.

It's a classic strategy that he has deployed in toxic immigration wars before: Tout his toughness and dedication to law and order while blaming Democrats for not fixing the system's problems.

It's a play that is likely to win approval from GOP base voters who saw in Trump a truth-teller on immigration whose tough policies and promise to build a wall could lacerate what they saw as liberal political correctness over the issue. Trump opponents see his policies as appeasing a hard-line stream of nationalist thought on the far right that is dedicated to stopping both illegal and legal immigration.

The President repeatedly pleads with his supporters to show up at the polls in November to fend off enthusiastic Democratic voters, knowing his political future in Washington depends on the GOP clinging onto the House and Senate.

GOP leaders are already worried the ongoing effort by moderates to force a House vote on the Obama-era Deferred Action for Childhood Arrivals program, or DACA, a program Trump moved to end last year but has been kept alive by the courts, will depress base turnout.

Trump chose to wage his latest political battle over his administration's policy of separating children from parents caught crossing the border illegally and liable for criminal prosecution. The controversy over the policy coincides with separate revelations that his administration lost track of nearly 1,500 children taken from parents awaiting adjudication of immigration cases and placed in foster homes or with sponsors.

The government's apparent disinclination or inability to find those children is an ill omen for thousands more who could be funneled to a similar fate under the Trump administration's enforcement drive.

The President poured oil on the fire on Saturday.

"Put pressure on the Democrats to end the horrible law that separates children from there (sic) parents once they cross the Border into the US," Trump tweeted.

Put pressure on the Democrats to end the horrible law that separates children from there parents once they cross the Border into the U.S. Catch and Release, Lottery and Chain must also go with it and we MUST continue building the WALL! DEMOCRATS ARE PROTECTING MS-13 THUGS. — Donald J. Trump (@realDonaldTrump) May 26, 2018

But there is no law requiring the government to separate kids of undocumented migrants or asylum seekers from their parents -- least of all one passed by Democrats.

It is the Trump administration's own policy to refer every person caught crossing the border illegally for federal prosecution, with the result that children are separated from their parents because they cannot legally follow them into the federal prison system.

The law on that issue was a bipartisan initiative, approved by unanimous consent and signed by Republican President George W. Bush, as CNN's Jake Tapper and FactCheck.org have reported. It does not require parents and children to be separated at the border.

The law requires unaccompanied minors from nations other than Mexico or Canada to be sent to the care of the Office for Refugee Settlement or relatives in the US while removal proceedings take place.

Tough deterrent

The administration has made no secret of the fact that it hopes the likelihood that families will be broken up will deter undocumented migration.

"If you smuggle illegal aliens across our border, then we will prosecute you. If you are smuggling a child, then we will prosecute you and that child will be separated from you as required by law," Sessions said.

"The children will be taken care of -- put into foster care or whatever. But the big point is they elected to come illegally into the United States and this is a technique that no one hopes will be used extensively or for very long," Kelly said.

Critics of Trump's policies say the President is willfully confusing the issue and exploiting the welfare of children as the administration drives home its zero tolerance immigration policy.

"You have a purposeful abuse of children for political gain," said David Leopold, the former president of the American Immigration Lawyers Association.

"(Trump) throws out a lie -- it is an intentional lie, to get the media and commentators focused on something that isn't true and his base believes it," Leopold said.

The plight of unaccompanied children who cross the border is the latest immigration storm whipped up by the Trump White House, and includes travel restrictions on people from some Muslim nations and the uncertainty facing of DACA recipients -- undocumented migrants brought to the US as kids.

The issue again raises the question of whether Trump's determination to stiffen immigration laws conflicts with the nation's fundamental values -- and a wider humanitarian duty to protect children.

In the same Saturday tweet, Trump also escalated his rhetoric on immigration in a way that is likely to further inflame the political atmosphere that will make any resolution of the issue even more elusive.

"Catch and Release, Lottery and Chain must also go with it and we MUST continue building the WALL! DEMOCRATS ARE PROTECTING MS-13 THUGS," Trump tweeted, highlighting the most divisive aspects on a debate that has been rocking US politics for more than a decade.

Monday afternoon, he continued in another tweet : "Remember, the Nancy Pelosi Dems are also weak on Crime, the Border and want to be gentle and kind to MS-13 gang members...not good!"

A Democratic lawmaker just introduced a bill to Repeal the GOP Tax Cuts (no chance). This is too good to be true for Republicans...Remember, the Nancy Pelosi Dems are also weak on Crime, the Border and want to be gentle and kind to MS-13 gang members...not good! — Donald J. Trump (@realDonaldTrump) May 28, 2018

Base pleasing play

Trump, of course, is not the only political figure who believes he can steer the immigration debate to his own advantage: for years, Democrats have appealed to Hispanic voters -- a core part of their own base -- and promised sweeping and comprehensive reform.

Texas Democratic Rep. Joaquin Castro is organizing a #WhereAreTheChildren rally in San Antonio on Thursday that is likely to be only one of many Democratic efforts to appeal to their own base following Trump's assault.

"When I think about the 1500 lost children and those who are systematically separated from their mothers at the border, I come back to the same thought: If we can't stop this in America we won't stop it anywhere," Castro tweeted on Sunday.

When I think about the 1500 lost children and those who are systematically separated from their mothers at the border, I come back to the same thought: If we can't stop this in America we won't stop it anywhere. #WhereAreTheChildren — Joaquin Castro (@JoaquinCastrotx) May 27, 2018

But no modern President has so consciously sought to peel open divides on immigration -- one of the most fundamental political issues across the Western world -- to the same extent as Trump has done.

In recent years, every effort to reshape America's immigration system dating back to the second term of the Bush administration has foundered on the vicious political divides opened up every time a key aspect of the debate flares up.

The controversy over family separation could also complicate attempts by some moderate Republicans to protect themselves from the fallout of Trump's tough rhetoric.

The rebellious lawmakers are attempting to force a vote against the House GOP leadership's wishes on a set of immigration bills.

The group is getting close to the 218 signatures it needs to automatically trigger a vote -- after winning the support of almost all Democrats.

House Republican leadership has been working with other lawmakers to try to force a vote on issues from border funding to citizenship in a way that could head off the revolt. But Trump's latest decision to fan the flames could throw all those careful calculations and sensitive efforts into the political trash can.