Donald Trump's plan to crack down on immigration includes using a range of tools to deport millions of people in the U.S. each year — from obscure laws to military funds to law enforcement officers from all levels of government.

Why it matters: History tells us such an effort would dramatically disrupt local communities and economies across the U.S. — and sow fear among the millions of people without legal status.

• If elected, Trump wants to mobilize ICE agents — along with the FBI, the Drug Enforcement Administration, federal prosecutors, the National Guard, and even state and local law enforcement officers — to carry out deportations of undocumented immigrants, a source familiar with the plan told Axios.
• Trump has long campaigned on anti-immigrant fears. "They're poisoning the blood of our country," he said at a rally last month, a line he repeats often.

Zoom in: Fast-track deportations — now reserved for recent crossers encountered near the border — would be expanded to apply to anyone who illegally crossed the border and couldn't prove they'd been living in the U.S. for more than two years.

• Trump would curtail the usual multistep deportation process by using an obscure section of the 1798 Alien and Sedition Acts to immediately round up and deport some migrants with criminal histories.
• The military would build massive sites near the border to hold people awaiting deportation.

It could evoke scenes from the 1950s, when more than 1 million undocumented Mexican immigrants were deported under President Eisenhower.

• It was the largest deportation operation in U.S. history. The vast majority of Americans alive today have never seen anything like it.
• The operation used military-style tactics to round up and house up to 1.3 million people from Mexico — and even some Mexican Americans who were U.S. citizens — according to federal immigration records. Scholars say there could have been many more.

The dollar cost of Trump's plan is unclear, and there's plenty of skepticism whether he could pull it off.

• Trump has made similar promises in the past, but deportation levels during his presidency never reached what they were under his predecessor, Barack Obama.
• The human costs of Trump's plan — to families, the economies of local communities, employers and more — could ripple across the nation, analysts say.

Between the lines: Among Trump's targets would be sponsors of unaccompanied minors who crossed the border without their parents, according to the source familiar with the plan.

• The government releases migrant children to these sponsors, who typically are the children's relatives — some without legal status.
• Hundreds of thousands of people also have been admitted into the U.S. under Biden's use of "parole," a program guaranteeing protection for two years. Trump's plan could target those with expiring protection for quick deportation.

Flashback: Besides the Eisenhower deportations, Trump's plan alludes to the forced "repatriations" of Mexicans in the 1930s.

• About 39% of the 10.5 million undocumented immigrants in the U.S. today are of Mexican nationality, so that group likely would be targeted again — along with an estimated 2.2 million undocumented people from Central America.

The intrigue: Unlike the mass deportations in the past, there would be pushback today from Democratic-led states, well-organized Latino advocacy groups and "sanctuary cities."

• Employers, community leaders and churches also would fight back, David J. Bier, associate director of immigration studies at the Cato Institute, tells Axios.
• "I can tell you that I, for one, would be a party to any lawsuit, any action, or any coalition" challenging Trump's plan, U.S. Rep. Sylvia Garcia (D-Texas) tells Axios.

Yes, but: Texas' aggressive actions on the border and the vocal support from other GOP-led states indicate Trump would have some state-level allies for his program.

• There are roughly 2.9 million undocumented immigrants just in Texas, Florida and Georgia.

State of play: Top policymakers acknowledge that immigrants — including those who recently crossed the border illegally — have played a role in easing inflation and helping the economy avoid a recession after the pandemic.

• It's a key reason why the Congressional Budget Office said this week it expects the United States' GDP to be a stunning $7 trillion greater over the next 10 years than it initially projected in 2023.
• A rebounding supply of workers helped heal the acute labor shortages in recent years that drove up wages and costs that businesses passed on to consumers.
• "[A] big part of the story of the labor market coming back into better balance is immigration returning to levels that were more typical of the pre-pandemic era," Federal Reserve chair Jerome Powell told "60 Minutes" last week.

Don't forget: Recent deportation surges damaged some local economies.

• In 2011, for example, unpicked crops rotted in Alabama after the state passed a harsh anti-immigrant bill, and as the Obama administration aggressively went after undocumented immigrants.