Through Republican and Democratic presidential administrations, the top federal prosecutor on California's border with Mexico has resisted going after people caught entering the U.S. illegally on their first try and instead targeted smugglers and serial offenders.
That approach may face a day of reckoning under President Donald Trump.
Attorney General Jeff Sessions' new directive on border crimes suggests prosecutors in California, Arizona, New Mexico and Texas will be forced to tow a narrow line.
He says each should consider felony prosecution for anyone convicted twice of entering illegally and develop plans to target first-time offenders and charge them with misdemeanors that could send them to jail for up to six months.
The president and attorney general typically set broad priorities for the Justice Department's 94 appointed U.S. attorneys and give them significant leeway. Prosecutors in Texas, New Mexico and Arizona have taken a stance closer to what Sessions wants.
Not so in California's Southern District covering about 140 miles (225 kilometers) of border from San Diego to Yuma, Arizona.
The federal government prosecuted 639 cases of illegal entry in California in the 2016 fiscal year, compared to 19,037 in the Southern District of Texas and 14,567 in the Western District of Texas, according to Syracuse University's Transaction Records Access Clearinghouse. South Texas is the busiest corridor for illegal crossings but that alone doesn't account for the huge disparity.
Peter Nunez, the top federal prosecutor in the district from 1982 to 1985 who believes the change is long overdue, said Trump is the first president since Dwight Eisenhower in the 1950s to make immigration enforcement a top priority and U.S. attorneys "will not be able to ignore that."
Immigration cases already make up about half of arrests in federal courts and more along the 2,000-mile border with Mexico. Any increase is likely to meet resistance from some judges and prosecutors in California.
James Stiven, a retired federal judge in San Diego, told the U.S. Sentencing Commission last year that the California border district chose its cases carefully, "preserving resources throughout the federal criminal-justice system rather than squandering them on unproven 'zero-tolerance' approaches." Of the proposed shift announced by Sessions on Tuesday, he said, "I can't imagine it would be well-received by the judges."
Carol Lam, who was named U.S. attorney for the Southern District of California in 2002 by President George W. Bush and forced to resign nearly five years later, prosecuted fewer immigrant smuggling cases and turned limited resources on "the most dangerous offenders," according to a report by the U.S. Justice Department's internal watchdog on the bungled dismissals of Lam and eight other U.S. attorneys.
The Justice Department's inspector general concluded Lam's low immigration and firearms caseloads led to her firing. Some Republican members of Congress and at least one Democrat, California Sen. Dianne Feinstein, questioned Lam's record on immigration.
But her successor, Karen Hewitt, took a similar approach to immigration from 2007 to 2010. By the time Hewitt left, most border districts had embraced zero-tolerance policies. There were 70 crossers shackled together at the ankles each day for lightning-quick appearances at the federal courthouse in Tucson, Arizona, and 80 a day in tiny Del Rio, Texas.
First-time offenders generally spent less than a week behind bars but their misdemeanor convictions exposed them to felonies if caught again.
Hewitt focused on smugglers and generally avoided prosecutions of first-time crossers. She told Joanna Lydgate for a 2010 article in the California Law Review that her approach was "consistent with what the public (in the Southern District of California) would like to see."
Laura Duffy, Hewitt's successor, hewed to the same strategy until she resigned in December to become a state judge. U.S. attorneys often change under new administrations, and Trump is expected to name permanent replacements soon.
Illegal entry prosecutions have plummeted in Arizona and New Mexico in recent years, so those districts may also be in for big changes.
Paul Charlton, the top federal prosecutor in Arizona from 2001 to 2007, said prosecutions require more judges, attorneys and prison beds. He questioned whether it's worthwhile to pursue lower-level immigration offenses with limited resources.
"Your rhetoric has to match your pocketbook if you want to go through this the right way, and even then, you have to realize that the deterrent effect (of prosecutions) will only go so far."