Trump argues that the Mexican government could stop the flow of drugs if it wanted to, but the caravan story helps show the flaws in that claim. The group wants to avoid “not only authorities who would seek to deport them, but gangs and cartels who are known to assault vulnerable migrants.” There’s extensive corruption in Mexico, including ties between police and drug traffickers, but successive Mexican governments have tried and failed to squash the drug trade.

Something similar is happening on Mexico’s southern border. The Mexican government has sought to crack down on crossings there, especially since Central Americans, post-Trump, have often decided that they won’t go to the U.S., but also won’t go home, and try to stay in Mexico instead.

There are many valid critiques to be made of Mexico’s policies on drugs and immigration, but there’s no indication that the only impediment to a solution is a lack of will by the Mexican government. Of course, it is a staple of Trump’s political worldview that simple force of will overcomes policy problems, but the American experience proves otherwise. For decades, the United States has fought a “War on Drugs” and tried various approaches to stop illegal immigration, but none of that—including “get tough” policies—has solved the problem.

Now, what about DACA? The president’s line on DACA has become ever more convoluted and contradictory. During the campaign, Trump promised to end DACA. Once in office, he did so, but he cited a procedural reason: He said he believed that the president did not have the authority to protect the so-called Dreamers, but he also called on Congress to enact a law protecting them. This was Trump’s attempt to split the political baby. He knew that policy was broadly popular, but also that his base hated it. He hoped he could please the base by canceling it, but dampen the political blow by transferring blame to Congress. Given how divisive the issue is, and how gridlocked Congress has been, he must have, or should have, known that DACA was dead on arrival there.

Over the last few weeks, the president has repeatedly tried to argue that the demise of DACA is Democrats’ fault, not his own or that of Republicans. Insofar as Democrats could have tried harder to pass the Dream Act when they controlled the House and Senate, this might be right, but Republicans worked to block the bill then. Obama then implemented the policy as an executive order, which stood until Trump revoked it in 2017.

Since then, the GOP-led Congress has shown little interest in passing a DACA replacement. During a public meeting in January, Trump briefly supported a “clean” DACA replacement, before being yanked back in line by horrified Republicans. Later that month, Trump rejected a deal from Senate Democratic leader Chuck Schumer that would have increased funding for border security and maybe even funded the wall, in exchange for a DACA fix. Now Trump contends that Democrats are to blame for there being no DACA fix.