When border crossings went down after Donald Trump’s inauguration, the White House was quick to take credit. Speaking at a press briefing in April of 2018, Homeland Security Secretary Kirstjen Nielsen noted that the Administration had seen a “precipitous drop” in unlawful border crossings.

“This ‘Trump effect,’ as many of you have referred to it and we have as well, on illicit border activity was undeniable,” she said.

In recent months, however, the number of people crossing the Mexican border illegally has spiked, hitting a 12-year high in March. And while there are complex reasons why this is happening, the president is particularly concerned that he will take the blame.

As with his campaign pledge to build a border wall, Trump’s fixation on the raw numbers of border crossings is a major factor in his decision-making on immigration. His recent decision to fire Nielsen and purge other top officials at the Department of Homeland Security stemmed in part from this concern, while his consideration of a number of dramatic actions is part of a larger effort to counter it.

Asked if the uptick in border crossings is driving Trump crazy, a former senior aide texted “not crazy — insane.”

“I understand he’s frustrated and he’s frustrated with good reason,” said Mark Krikorian, executive director of the Center for Immigration Studies, which advocates for reducing immigration levels. “His options are limited without congressional actions, but there are some things he can do.”

That list, as reported by Axios, includes potential executive actions to limit the reasons people seeking in asylum in the U.S. can claim, stop allowing asylum-seekers to get work permits while their cases are being handled and detain migrant children for longer periods than currently allowed.

Trump also recently mused publicly about closing the border to all traffic, reportedly encouraged border agents to flout asylum law in a meeting and pointedly argued that the end of a controversial child separation policy was encouraging more crossings, even as said he wouldn’t reinstate it.

“Once you don’t have it,” Trump said about family separations on Tuesday, “that’s why you see many more people coming. They’re coming like it’s a picnic because ‘let’s go to Disneyland.'”

But while Trump often claims that U.S. policies are the driving force behind migration, the recent spike is driven far more by problems elsewhere.

The collapse of the rule of law and economic troubles in three Central American countries — Guatemala, Honduras and El Salvador — have convinced tens of thousands of families from those countries to pin their hopes on making the dangerous trek north to find both safety and work. A study funded by the Department of Homeland Security and published in 2018 found that “wages for people migrating illegally to the United States tend to be about 13 to 14 times the wages available to them in their home countries.”

The most dramatic increase is coming from people crossing illegally with children. Border Patrol agents apprehended 53,077 people crossing illegally with family in March, an increase of 45% over the 36,531 such people apprehended the month before, according to figures released Tuesday by U.S. Customs and Border Protection.

Migrant families in detention present unique challenges to immigration officials. Children must be released from detention facilities with 20 days of being detained to comply with a 1997 court settlement. That release often lengthens the amount of time children and their family members are allowed to stay in the U.S. while they wait for their asylum claims to be heard by a judge, since people held in detention get put on a faster moving immigration court docket.

The Trump Administration attempted to address this last year with the short-lived child-separation policy, which separated migrant kids from their parents with the goal of speeding up deportation of their parents and deterring other families from making the journey. But Trump eventually backed off of the policy in the wake of a national uproar.

Trump has also sought to influence the three countries that are sending migrants.

For several years, the U.S. has invested billions in building up the police forces and economies of Central American countries in a long-term effort to improve the lives of people living there so there is less incentive for them to migrate. While those programs have had mixed results, Trump has bristled at the idea of sending more money, insisting that the local governments should first do more to prevent their citizens from leaving. Last month, Trump said he would cut aid payments if more wasn’t done to stem migration.

“We were paying them tremendous amounts of money. And we’re not paying them anymore. Because they haven’t done a thing for us. They set up these caravans,” Trump said on March 30.

And in recent weeks, he’s considered drastic changes to the system for seeking asylum in the U.S.

If migrants make it into the country — illegally or legally — they have the right to apply for asylum. While their cases are being considered, they can work legally in the US. Trump Administration officials are considering instituting tougher screening for asylum claims. But, if implemented hastily, that plan runs the risk of being blocked by the courts, as was Trump’s earlier order in November that asylum seekers can be denied entry to the U.S. and that migrants can be sent to Mexico while their claims are heard.

The recent increases have prompted Trump to oust Nielsen and deputy Homeland Security Secretary Claire Grady. Immigration hardliners had long felt Nielsen, who came into the department with experience in cybersecurity, didn’t have a strong enough grasp of immigration policy.

“I think she was dumped into the deep end without a life jacket and she sank,” said Rosemary Jenks, the director of government relations for NumbersUSA, an organization that advocates for lower immigration levels.

White House officials are also considering replacing DHS general counsel John Mitnick as well as the head of U.S. Citizenship and Immigration Services Francis Cissna, who critics argue have slow walked Trump’s demands for tougher immigration regulations. But both officials have also earned praise from some long-time immigration hawks as shrewd right-wing legal minds who are trying to implement policies that won’t be held up in court.

All of this leads up to a situation that is politically difficult for the President. It is unclear if any of these actions will have an effect on the number of border crossings, even if they aren’t held up in court or cut short after public protest.

But for Trump, some of his close advisors have argued, the fight is often enough. Former White House strategic advisor Steve Bannon told TIME in February that a public debate over the limits of Trump’s executive powers on immigration would serve him better than headlines on the minutia of Congressional investigations. Last year, White House adviser Stephen Miller was arguing internally for months to have a government shutdown over wall funding in order to put Democrats in the position of arguing against more border security.

“With regards to the wall, the President has shown to his supporters that he is willing to declare a national emergency,” Kris Kobach, former Kansas Secretary of State and on the short list for replacing Nielsen as DHS secretary, told TIME. “Whatever amount of barrier is built before November 2020, the President has shown that he is willing to fight for it, even if it is not every mile that he might have wanted.”

These potentially drastic moves may help keep Trump’s base close to him, but they also risk firing up Democratic voters who disagree. Trump tried to make the 2018 midterms into a referendum on immigration, but weeks of talk about migrant caravans didn’t help Republicans stave off deep losses in the House.

But with border crossing numbers going up, Trump seems locked into the strategy, and his re-election campaign is focusing on portraying him as an active and responsive president on the issue.

“It’s tackling issues that past presidents have either not been willing to do or have been unable to do,” Kayleigh McEnany, press secretary for Trump’s 2020 campaign, told TIME. “And with the border, it’s one where no past presidents have been willing to take the political initiative to build a barrier structure. This president is doing that unmistakably. Meanwhile, Democrats are sitting on the sidelines doing nothing.”

Contact us at letters@time.com.