Attorney General Jeff Sessions on Wednesday unloaded on California Democrats who push a “radical, open borders agenda,” as his Justice Department sued the state over its immigration policies -- warning that there “will be no secession.”

Sessions spoke at an event for California law enforcement and a day after the Justice Department announced it was filing a lawsuit against the “sanctuary city” state over three pieces of legislation that it said interferes with federal immigration policy.

TRUMP DOJ SUES CALIFORNIA OVER 'INTERFERENCE' WITH IMMIGRATION ENFORCEMENT

In his remarks, Sessions noted “worrisome” trends as violent crime increased in 2014 and 2015, particularly a surge in homicide and drug availability. He said that a lawful immigration system was part of tackling such trends.

Sessions said that while America admits the highest number of legal immigrants in the world, the American people deserve a legal, rational immigration system that protects the nation and preserves the national interest.

“It cannot be the policy of a great nation to reward those who unlawfully enter its country with legal status, Social Security, welfare, food stamps, and work permits and so forth. How can this be a sound policy?” he asked.

“Meanwhile, those who engage in this process lawfully and patiently and wait their turn are discriminated against, it seems, at every turn.”

Turning to California, he described "open borders" policies that refuse to apprehend and deport illegal immigrants as a “radical, irrational idea that cannot be accepted” and rejected the right of states to obstruct federal immigration law.

“There is no nullification. There is no secession,” he said. “Federal law is the supreme law of the land. I would invite any doubters to go to Gettysburg, or to the tombstones of John C. Calhoun and Abraham Lincoln."

He then tore into Oakland Mayor Libby Schaaf, who tipped off the public to an immigration raid in the San Francisco Bay Area last week -- a move he said led to as many 800 illegal immigrants evading capture and put both residents and law enforcement at risk.

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

In defending the lawsuit, he accused California lawmakers of passing laws that are not only unconstitutional, but also a “plain violation of federal statute and common sense.”

“Importantly, these laws are harmful to Californians, and they’re especially harmful to our law enforcement,” he said.

"I did what I believe was right for my community as well as to protect public safety," Schaaf said Friday, according to NBC Bay Area. "People should be able to live without fear or panic and know their rights and responsibilities as well as their recourses."

Democrats have pushed back against the Trump administration's crackdown on so-called “sanctuary cities” where officials are ordered not to cooperate with federal authorities.

House Minority Leader Nancy Pelosi, D-Calif., said Wednesday that the lawsuit marked “a new low” from the Trump administration and said the president was abusing the legal system “to push his mass deportation agenda.”

PELOSI SLAMS CALIFORNIA ICE RAID AS 'UNJUST AND CRUEL' AMID OUTCRY OVER MAYOR'S TIPOFF TO IMMIGRANTS

"The people of California will not be bowed by the Trump administration's brazen aggression and intimidation tactics,” Pelosi said. “Californians will continue to proudly keep our doors open to the immigrants who make America more American. We will fight this sham lawsuit and will fight all cowardly attacks on our immigrant communities."

But in his remarks, Sessions appeared to be happy to fight, promising that the administration will win the fight and protect law enforcement in doing their jobs.

“California is using every power it has, and some it does not, to frustrate federal law enforcement,” he said. “So you can be sure I’m going to use every power I have to stop them.”

Sessions has been a longtime favorite of Trump’s base due to his fight against illegal immigration as an Alabama senator. In a 2015 handbook to fellow GOP lawmakers, he called “immigration reform” a “legislative honorific almost exclusively reserved for proposals which benefit everyone but actual American citizens.”

But Sessions quickly fell out of favor with President Trump, particularly over his decision to recuse himself from investigations related to alleged ties between Russia and the Trump campaign.

Trump has lashed out against Sessions on a number of occasions, and has even said he would not have appointed Sessions if he knew what he was going to do.

Last week Trump blasted Sessions over his decision to ask the inspector general to review alleged surveillance abuse by intelligence agencies.

Trump complained that the IG is an “Obama guy” and such an investigation will “take forever” (though the inspector general has served under presidents of both parties).

"Why not use Justice Department lawyers? DISGRACEFUL!" Trump tweeted.

Fox News’ Bill Mears contributed to this report.