Natural disasters in Central America, economic devastation, gang wars, political oppression, and a new administration are all driving the sharp rise in U.S.-Mexico border crossings — a budding crisis for President Biden.

Why it matters: Migration flows are complex and quickly politicized. Biden's policies are likely sending signals that are encouraging the surge — but that's only a small reason it's happening.

• Circumstances in foreign nations are forcing migrants to leave (push factors) while the situation in the U.S. draws them (pull factors.)
• Many have been forced to flee harrowing troubles in their home countries, experts say. Others are hoping for better economic prospects.

What's new: It's been just a few months since two devastating hurricanes left thousands homeless in Honduras. The country's largest newspaper, Diario El Heraldo,reported that many remain in Tegucigalpa shelters with no place to go.

• The storms, drought, and pandemic have sparked food shortages throughout Central America.
• Violence among gangs in Honduras also rages, even in rural areas, forcing residents to flee to el Norte. 
• Shelters in Mexico also are reporting a surge in Central American migrants.  
• “We have a tremendous flow and there isn’t capacity. The situation could get out of control,” said Gabriel Romero, a priest who runs a migrant shelter in the southern Mexican state of Tabasco, told The Associated Press.

Experts said the shift from the Trump administration's crackdown to the perception of a more welcoming Biden administration also is contributing to migrants' hope for the U.S. as a haven.

• Regardless of the preparedness of the border systems, migrants who have been considering coming to the U.S. likely see now as their window to make the often dangerous trip, experts said.
• "We know plenty enough about migration to know that the most reliable sources of information for intending migrants tend not to be what public officials say — but what it is that they're hearing through their own networks... as well as through the smugglers," the Migration Policy Institute's Doris Meissner told Axios.

Between the lines: The increase of migrant children from Central America has been increasing for weeks.

• Border Patrol agents apprehended more than 900 unaccompanied migrant children in December in the El Paso sector, which includes Far West Texas and New Mexico, El Paso Matters reports.
• That’s the highest number since June 2019, according to Customs and Border Protection data.

The big picture: In addition, there are several long-term trends that contribute to the uptick in migrants seeking asylum in the U.S.

• Border numbers tend to rise with warmer weather, peaking around May. The numbers are unusually high right now, but the timing follows a typical seasonal pattern.
• Migrants often come from Honduras, Guatemala, and El Salvador, which have "had seriously desperate conditions for a long time," Meissner said. "It's a range of things. Obviously, the issue of jobs and economy and poverty, etc. But it's overlaid with severe violence and gang recruitment and lots of domestic abuse."
• Climate change has impacted the crucial coffee-growing industry in Guatemala, which has been a contributing factor to migration from there.

There is also a long history of economic migration from Central American countries and Mexico.

• "The country of Honduras has become incredibly dependent on migration to the United States and the incomes that migrants in the U.S. get and send back to their families," said the University of Rochester's Daniel Reichman, an expert in Honduran migration.
• The asylum system was not intended for economic migration, but it is often the only pathway available. Reichman argues that U.S. immigration laws should better reflect the desire for many migrants to work in the country, but then return home.

The backstory: The current surge of child migrants at the border is not the first. Former President Donald Trump had a family and child crisis in 2019, and former President Barack Obama dealt with another one in 2014.

• "If you don't launch a Marshall Plan for Central America, you're not going to stop the people from leaving their countries due to violence and economic devastation," said Fernando García, executive director of the Border Network for Human Rights.

The bottom line: "In terms of the way analysts and politicians see these issues, it tends to fall into really emphasizing the push or really emphasizing the pull," Meissner said. "But the fact of the matter is: It's both."