You can boil down Trump’s 2016 domestic-policy pitch to three core promises:

1. Jobs, jobs, jobs. Check.

2. Conservative Supreme Court justices. Check and check.

3. Secure borders. Uhhh…

“Trump 2020: Two out of three ain’t bad.”

Border Patrol agents arrested 16,658 family members in September, the highest one-month total on record and an 80 percent increase from July, according to unpublished Department of Homeland Security statistics obtained by The Washington Post…

The latest DHS figures show 107,212 members of “family units” were taken into custody during fiscal 2018, obliterating the previous high of 77,857 set in 2016…

Immigration and Customs Enforcement has about 3,300 detention beds at three “family residential centers,” but five times as many parents and children are crossing each month. The volume has overwhelmed Border Patrol stations and prompted mass releases.…

DHS officials have seen a particularly large increase this year in families arriving from Guatemala, where smuggling guides have been encouraging migrants to bring children with them to avoid deportation.

So that’s why he’s suddenly ready to play hardball with Latin American countries. Last year at this time the news was that illegal border crossings had dropped, putting Trump on track to keep the policy pledge that matters most to his populist base. But it didn’t hold — and ironically, the “family separation” saga of this past summer may be partly responsible. A senior official in Trump’s administration tells WaPo that the public outcry over separating families and Trump’s eventual capitulation on it sent a “clear signal” to foreigners that they’d be treated leniently if they jumped the border — especially if they brought kids with them. So that’s what they’re doing. As noted in the excerpt, not only are more illegals showing up with kids, there are so many that ICE can’t even hold them. It’s a catch-and-release nightmare.

Which means a few things going forward. One: Kirstjen Nielsen probably isn’t long for this administration. Trump’s been blaming her for months for not delivering on lower illegal immigration levels. December will mark one full year on the job at DHS for her. If Trump finally ousts her mentor, John Kelly, during the lame-duck session it may be that he’ll decide to get rid of Nielsen too, especially if the GOP picks up Senate seats in November and will have a more robust majority to confirm a new nominee next year. He’s not a leader who accepts responsibility for the failures of others. If the immigration trend doesn’t reverse soon, someone will be sacrificed. Nielsen’s the obvious choice.

Two: McConnell keeps reassuring people that he doesn’t think there’ll be a shutdown at the end of the year over lack of funding for the wall despite Trump’s many threats during his presidency to force a confrontation on the issue. With illegal family crossings soaring, POTUS may now believe he has no choice but to follow through in the name of doing something to try to reverse the trend. Delivering on his most famous campaign promise is the obvious option. How he’s going to get that funding so long as Chuck Schumer has filibuster power is hard to see, though. And in theory the standoff could bleed into the new year — when a new Democratic House majority is likely to be seated. Then Trump will have problems in both houses of Congress instead of just one. What’s he prepared to give the Dems in exchange for the wall? Some Republicans are already thinking about it, anxiously.

Three: Even if Trump got wall funding, it’ll be years before it’s built. Gotta do something in the meantime to deter illegals from coming and bringing their kids with them. He and Stephen Miller are working on a new plan.

One option under consideration is for the government to detain asylum-seeking families together for up to 20 days, then give parents a choice — stay in family detention with their child for months or years as their immigration case proceeds, or allow children to be taken to a government shelter so other relatives or guardians can seek custody.

That option — called “binary choice” — is one of several under consideration amid the president’s frustration over border security. Trump has been unable to fulfill key promises to build a border wall and end what he calls “catch and release,” a process that began under past administrations in which most detained families are quickly freed to await immigration hearings. The number of migrant family members arrested and charged with illegally crossing the border jumped 38 percent in August and is now at a record level, according to Department of Homeland Security officials.

“Catch and release” of the parent would end under either option in “binary choice” but the status of children would be iffier. Under the Flores settlement they have to be released or sent to an HHS facility within 20 days; to allow indefinite detention of kids under the first option would require amending the Flores settlement by statute (impossible with a Democratic House) or issuing new DHS regulations, but that’ll take months and would certainly end up tangled up in lawsuits for additional months beyond that. Also, where will families be held even if the new regs survive a court challenge? Trump doesn’t just need money for the wall, he needs money for more detention centers — a lot more if indefinite detention of entire families is on the table here. Would Democrats give him that next year in the name of making shelters for illegals as well-funded as possible or would they deny it in hopes of leaving him no choice but to reinstate “catch and release”? Probably the latter, I would think. They want open borders. Denying funding for detention facilities gets them closer to their goal.