(CNN) There is a very important change in Donald Trump's rhetoric on the subject of immigration recently and it has everything to do with Congress and the approaching midterm elections.

There's serious danger in ascribing any sort of long-term strategy to Trump's tweets, but you can see him concocting a campaign issue here with a new focus on changing immigration laws.

He's been on a tear about "laws," tweeting four times about them in the four days of April. That's more tweets about immigration laws in four days than tweets about immigration laws than the entire rest of his presidency (four).

Reading his nine April immigration law tweets in order gives you a somewhat coherent view of where he's going with this. The following includes, in order, two tweets from April 1, five tweets from April 2, and one tweet each from April 3 and 4:

From April 1:

Border Patrol Agents are not allowed to properly do their job at the Border because of ridiculous liberal (Democrat) laws like Catch & Release. Getting more dangerous. "Caravans" coming. Republicans must go to Nuclear Option to pass tough laws NOW. NO MORE DACA DEAL!

Mexico is doing very little, if not NOTHING, at stopping people from flowing into Mexico through their Southern Border, and then into the U.S. They laugh at our dumb immigration laws. They must stop the big drug and people flows, or I will stop their cash cow, NAFTA. NEED WALL!

From April 2:

Mexico has the absolute power not to let these large "Caravans" of people enter their country. They must stop them at their Northern Border, which they can do because their border laws work, not allow them to pass through into our country, which has no effective border laws.....

JUST WATCHED Ramos: Trump is the real wall on immigration Replay More Videos ... MUST WATCH Ramos: Trump is the real wall on immigration 00:51

...Congress must immediately pass Border Legislation, use Nuclear Option if necessary, to stop the massive inflow of Drugs and People. Border Patrol Agents (and ICE) are GREAT, but the weak Dem laws don't allow them to do their job. Act now Congress, our country is being stolen!

Mexico is making a fortune on NAFTA...They have very strong border laws - ours are pathetic. With all of the money they make from the U.S., hopefully they will stop people from coming through their country and into ours, at least until Congress changes our immigration laws!

As ridiculous as it sounds, the laws of our country do not easily allow us to send those crossing our Southern Border back where they came from. A whole big wasted procedure must take place. Mexico & Canada have tough immigration laws, whereas ours are an Obama joke. ACT CONGRESS

Honduras, Mexico and many other countries that the U.S. is very generous to, sends many of their people to our country through our WEAK IMMIGRATION POLICIES. Caravans are heading here. Must pass tough laws and build the WALL. Democrats allow open borders, drugs and crime!

From April 3:

The big Caravan of People from Honduras, now coming across Mexico and heading to our "Weak Laws" Border, had better be stopped before it gets there. Cash cow NAFTA is in play, as is foreign aid to Honduras and the countries that allow this to happen. Congress MUST ACT NOW!

From April 4:

Our Border Laws are very weak while those of Mexico & Canada are very strong. Congress must change these Obama era, and other, laws NOW! The Democrats stand in our way - they want people to pour into our country unchecked....CRIME! We will be taking strong action today.

Got all that? Set aside the threats to Mexico and Honduras for now and focus instead on the larger point he's making in this series: Canada and Mexico have strong laws. The US has weak laws put in place by Democrats. We must change the laws.

There is a lot that is wrong with the arguments Trump makes here (and his similar pronouncements during appearances with Baltic leaders at the White House Tuesday). His main gripes have to do with the idea of people seeking asylum and on protections for immigrants in custody.

CNN's Tal Kopan has done some very good work fact checking him on immigration and US laws.

You don't need a Ph.D. in political science to know that lawmakers make the laws. Nor do you need to pay too much attention to politics to know that lawmakers are up for election in November and Republicans, largely thanks to Trump's abysmal approval rating, are facing some very serious headwinds, particularly in the House.

CNN's Jeremy Diamond wrote this week about Trump's increasing interest in the midterms and how he's crafting strategy now that his former communications director Hope Hicks is no longer by his side.

Of course, his miraculous 2016 victory was built largely on the issue of immigration and his pledge to build a border wall. He's danced around his inability to get Congress to approve and fund the border wall in full, although there is money for it in a recent spending bill. Calling US immigration laws weak and in need of fixing feels a lot like a riff on the immigration fears he stoked in 2016.

A bold prediction for the time between now and November is that Trump will be talking a lot more about how weak he thinks US laws are and how he'll need a Republican Congress to change them.