I think it is no coincidence that the night before he kicks off his re-election campaign in Orlando (in front of a crowd of 20,000 with many thousands more gathered outside), President Trump announced that "millions" of illegal aliens are starting to be deported by ICE.

He did so on Twitter, while simultaneously noting that Mexico and Guatemala are implementing or about to implement measures that will diminish the flow of third-world country nationals transiting Mexico.

In other words: stanch the new flow while expelling those already here illegally.  Even before the border wall is completed.

Delivering on his key promise of 2016.

Next week ICE will begin the process of removing the millions of illegal aliens who have illicitly found their way into the United States. They will be removed as fast as they come in. Mexico, using their strong immigration laws, is doing a very good job of stopping people.......

— Donald J. Trump (@realDonaldTrump) June 18, 2019

....long before they get to our Southern Border. Guatemala is getting ready to sign a Safe-Third Agreement. The only ones who won’t do anything are the Democrats in Congress. They must vote to get rid of the loopholes, and fix asylum! If so, Border Crisis will end quickly!

— Donald J. Trump (@realDonaldTrump) June 18, 2019

This positions Trump as being effective even without Congress cooperating with legal changes and more border wall funding.

I also expect that he anticipates that one or more federal judges will seek to halt ICE deportations.  My sense is that he wants a case on which he can challenge the validity of 50-state injunctions being issued by one federal judge.  Deportations of people here illegally maybe the test case he wants.

Hat tip: Roger Luchs.