Attorney General Jeff Sessions went to war with California this week, suing the state for allegedly violating federal laws by passing new protections curtailing federal immigration authority in the state.

And during a speech declaring that war on Wednesday, Sessions did not go after California’s Governor Jerry Brown or Attorney General Xavier Becerra—both named in the suit. Instead, he took time to single out a leader who, until a week ago, had largely operated outside any national spotlight.

“How dare you needlessly endanger the lives of our law enforcement officers just to promote a radical open borders agenda,” Sessions said.

Trump’s attorney general was describing Oakland Mayor Libby Schaaf, a Democrat who ignited a firestorm of criticism from the right when she warned immigrants in her city that Immigration and Customs Enforcement agents were planning raids.

Sessions’ comments capped off a week in which Schaaf, 52, became the newest villain across conservative media.

Her decision to forewarn undocumented immigrants living in the U.S. about the raids has gotten some coverage in local and some mainstream national news outlets—by and large, however, taking a backseat to ongoing White House chaos.

But nowhere has it dominated the news cycle as it did on Fox News and among right-wing digital outlets, which have labeled Shaaf the “Gang Lookout Mayor,” parroting the Trumpian suggestion that undocumented immigrants are criminals and gang members, and cited ICE claims that the mayor’s warning helped 800 targeted immigrants evade agents.

Stories about Schaaf sat at the top of Fox News’ website for most of Tuesday and Wednesday, eclipsing other major stories like adult-film star Stormy Daniels’ lawsuit against Trump, turmoil over the president’s decision to raise tariffs on steel and aluminum, national economic council director Gary Cohn’s resignation from the White House, and developments in special counselor Robert Mueller’s Russia probe.

According to a search of cable-monitoring service TVEyes, Fox News has mentioned the Oakland mayor more than a hundred times in the past seven days since the story broke, repeatedly arguing she put ICE agents in danger by warning immigrants of upcoming raids.

“You are putting ICE members at work, border patrol people’s lives in jeopardy, the communities in jeopardy because most of them are known criminals,” Fox News host Sean Hannity said on Tuesday. “There is no excuse for what this woman, this Oakland mayor, is doing by putting people's lives in jeopardy.”

“If you guys think it works out well for you to have these criminal aliens, gang bangers, people transporting weapons, domestic abusers released into the system to get a warning from the mayor in Oakland, flee the scene, come back later when ICE is gone—if you think that's going to work out well for you, God bless you,” his colleague Laura Ingraham also said on-air last week. “I hope it works out.”

“Mayor Libby Schaaf has taken the side of illegal aliens over American citizens,” Tucker Carlson insisted. “Maybe to her credit she is doing it right out in the open. She is trying to sabotage federal immigration enforcement.”

While Schaaf has been blasted almost every night on Fox’s highly rated primetime shows, the network’s cable rivals have barely picked up the story.

As of Wednesday morning, CNN had mentioned the mayor in just two segments, while MSNBC had mentioned the story once.

Meanwhile, conservative sites have gone further than even Fox’s blustery primetime hosts, pressing Sessions to arrest Schaaf.

“DRAG HER ASS INTO JAIL,” a Breitbart News headline blared.

“They need to lock her up,” wrote a columnist for conservative commentary site Townhall. “If Libby wants to pay lip service to the rule of law while harboring criminal illegal aliens in our country, then let’s make her dreams come true. Lock her up, Sessions!”

In an interview on Wednesday, Breitbart News’ Joel Pollack told Sessions that the “number one question” people had for the top attorney was whether he will take legal action directly against Schaaf.

“We are in communication with [Acting ICE] Director [Thomas] Homan, and we look forward to reviewing the facts as they present them to our attorneys,” Sessions coyly replied. “But I couldn’t comment beyond that.”

For their part, immigration advocates pushed back.

Immigration attorney David Leopold said Schaaf was helping immigrants know their rights, and was not obstructing justice, as some conservative pundits argued.

"What she was doing was nothing more than telling people what their rights are," Leopold said. " She didn't tell people to hide, she didn't tell people to obstruct she didn't do anything that would violate the law."

"That's why they're taunting her, but they don't have a particular statute that they're pointing to. Because there is none."

For her part, Schaaf has insisted that her warning was meant to help keep families together— a tactic she argued has lowered Oakland’s crime rate significantly.

"How dare you vilify members of our community by trying to frighten the American public into thinking all undocumented residents are dangerous criminals," she said following Sessions' comments on Wednesday. "How dare you distort the reality about declining violent crime in a diverse sanctuary city like Oakland, California to advance your racist agenda."