The Trump administration Tuesday sued California over its sanctuary policies for undocumented immigrants, setting off a chorus of near-unanimous defiance from California lawmakers.

Attorney General Jeff Sessions will lay out the details of the lawsuit Wednesday in a speech expected to start at 8:05 a.m. at The Sawyer hotel in downtown Sacramento, where he will address members of the California Peace Officers Association.

Hundreds of protesters were headed to the capital Tuesday in advance of his appearance.

“The Department of Justice and the Trump Administration are going to fight these unjust, unfair, and unconstitutional policies that have been imposed on you,” Attorney General Jeff Sessions will tell the officers, according to prepared remarks. “We are fighting to make your jobs safer and to help you reduce crime in America. And I believe that we are going to win.”

The lawsuit, filed Tuesday evening in the U.S. Eastern District of California, marks a turning point in the ongoing battle between the Trump administration and state and local jurisdictions over how far cities and states can go to block their officers from enforcing federal immigration law.

The suit targets three California laws–Senate Bill 54, Assembly bill 450 and Assembly bill 103 – that the federal government say violate the supremacy clause of the U.S. Constitution and interfere with the enforcement of federal immigration laws.

It names both California Gov. Jerry Brown and Attorney General Xavier Becerra personally as defendants.

“The Trump administration is now going on offense and is going to use any tools in its tool box to enforce immigration laws,” said a U.S. source who has spoken about the plans with senior administration officials. “They have no expectation in winning in District Court or the 9th Circuit. This is a case that is intended to be ultimately successful in the Supreme Court.”

State officials dismissed the idea that Trump would prevail and struck a defiant tone.

“At a time of unprecedented political turmoil, Jeff Sessions has come to California to further divide and polarize America,” Governor Brown said in an emailed statement. “Jeff, these political stunts may be the norm in Washington, but they don’t work here. SAD!!!”

California Senate President pro Tempore Kevin de León, D- Los Angeles, said Tuesday that he was confident that Senate Bill 54 was on solid legal ground.

“With regards to SB 54, there was a reason why from the beginning of President Trump’s election that I hired the former U.S. Attorney General of the United States, Eric Holder, and that was to receive expert counsel on federal issues,” de Leon said. “If it galls the (current) U.S. Attorney General and the president that we won’t help enforce their racist, xenophobic immigration policies, then I say tough.”

Sacramento Mayor Darrell Steinberg, a former leader of the California Senate, echoed that defiance from Washington, D.C. where he had traveled for a business advocacy trip. “Their legal strategy around these issues has not been impressive, so whatever,” Steinberg said.

“If he wants to come to … further try to intimate the city, the state, but more importantly the Dreamers and the hard working families, he might as well cancel his flight, because we’re going to react in the same way we have reacted consistently,” Steinberg said. “We are a proud safe haven, a proud sanctuary city, a proud sanctuary state and we stand with our neighbors.”

California became a sanctuary state at the start of the year with implementation of Senate Bill 54, also called the California Values Act, which restricts how and when state law enforcement can interact with federal immigration authorities. The statute quickly became a flashpoint between the Trump administration and state lawmakers. Assembly bill 450 created rules for how employers must handle federal immigration audit requests, commonly called I-9 audits.