States have started complying with President Donald Trump's request last week to send National Guard members to the U.S.-Mexico border, his latest move to strengthen security and reduce illegal immigration.
The governors of Texas and Arizona have deployed hundreds of troops to the border in recent days. California Democratic Gov. Jerry Brown said he would send roughly 400 National Guard troops to the border, but restrict them from enforcing "federal immigration laws" — a rebuke of Trump's immigration policies.
The moves come one week after Trump vented about border security in a series of tweets, and then signed an order requesting the deployment of National Guard troops to the country's Southern border. Days later, the White House confirmed plans to deploy an estimated 2,000 to 4,000 National Guard members to support federal agents along the border.
The order sent states along the southern border scrambling to decide if and how many troops they would send to meet Trump's request. As the deployments ramp up, here's what you need to know:
Why is this happening?
Trump's deployment order represents another step toward fulfilling one of his core campaign promises: strengthening border security and reducing what he says is an influx of undocumented immigrants, drugs and crime.
The Trump administration has also proposed laws to make applying for and granting asylum more difficult and moved to end "catch and release," which allows for immigrants that arrive at the border to be released from detention while they wait for their case to be heard.
Trump's decision last week came as he expressed concern on Twitter over the caravan of several hundred Central American immigrants in Mexico heading towards the U.S. border.
According to media reports, the caravan was organized by the nonprofit group Pueblo Sin Fronteras to support Central American migrants seeking asylum in both Mexico and the United States.
What will the troops do?
States will manage the National Guard troops they deploy, though deployment is being funded by the federal government. It's unclear what the cost of the total operation will be.
At a press conference last Thursday, the Pentagon clarified that the National Guard will aid with, "aviation, engineering, surveillance, communications, vehicle maintenance and logistical support."
Troops will be barred from interacting with migrants directly and cannot make arrests.
In an memo sent last Friday, Defense Secretary James Mattis approved funding to cover the deployment of up to 4,000 National Guard agents through Sept. 30. States can decide to allocate additional National Guard troops as time goes on.
What states are sending troops?
Texas Republican Gov. Greg Abbott was the first to respond to Trump's request, ordering 250 National Guard agents to the border. On Monday, Abbott said he would send an additional 1,000 troops. Arizona Republican Gov. Doug Ducey has sent 225 agents, and might reportedly send an additional 113 troops. New Mexico has also expressed support for Trump's plan.
Brown took a different approach in California, agreeing to send troops but expressing his displeasure with the politics surrounding Trump's decision.
"This will not be a mission to build a new wall," Brown wrote, referring to Trump's oft-stated goal of building a border wall. "It will not be a mission to round up women and children or detain people escaping violence and seeking a better life."
Governors in other states have also criticized Trump's request. Nevada Republican Gov. Brian Sandoval (R), came out against the deployment order. Oregon Democratic Gov. Kate Brown took to Twitter to say she was "troubled" by Trump's plan and would not send troops.
With border deployment, Trump joins Bush, Obama
This is not the first time National Guard troops have been deployed to the border. Presidents Barack Obama and George W. Bush also sent troops to the border, with mixed results.
Bush deployed National Guard troops to the border in 2006. The deployment lasted two years and cost an estimated $1.2 billion. After the mission, Army National Guard Commander Maj. David M. Church said both the National Guard and DHS did not communicate effectively and had little time for preparation.
Obama's deployment, called Operation Phalanx, lasted from July 2010 to Sept. 2011. Intended to help reduce drug and human trafficking, the effort cost an estimated $110 million. At the time, critics argued the deployment was not worth the cost.