SF City Attorney Dennis Herrera filed a lawsuit Tuesday challenging President Trump's executive order that threatens to withhold federal funds from so-called Sanctuary Cities, becoming the first city the nation to do so. Reuters broke the news, and the San Francisco Business Times published some of the text of the lawsuit, noting that it reads, "In blatant disregard of the law, the President of the United States seeks to coerce local authorities into abandoning what are known as 'Sanctuary City' laws and policies."

Many have questioned the constitutionality of the order under the Tenth Amendment since it was signed last week, and San Francisco city leaders have put up a united front in standing firmly at odds with the Trump Administration's agenda. On Monday, Mayor Ed Lee, Police Chief William Scott and Sheriff Vicki Hennessy wrote a joint letter to the Department of Homeland Security, as the SF Chronicle reports, stating in part, "Pressing local jurisdictions to become entangled in federal immigration enforcement betrays that trust and undermines the work our public safety departments have done to improve relations with our residents. We will not jeopardize the public safety of our communities to do the job of the federal government.” The letter said firmly that the city "declines to participate in any agreements" laid out in Trump's two executive orders, and that city public safety agencies would not enforce federal immigration law.

The city's lawsuit, meanwhile, goes further to say, in part:

San Francisco is a city of immigrants, many of whom are undocumented, who come here to live, work, and raise families. San Francisco is safer when all people, including undocumented immigrants, feel safe reporting crimes. San Francisco is healthier when all residents, including undocumented immigrants, access public health programs. And San Francisco is economically and socially stronger when all children, including undocumented immigrants, attend school.

Using city and county resources for federal immigration enforcement breeds distrust of local government and officials who have no power to change federal laws, and can also wrench apart family and community structures that support residents and thus conserve resources. For these reasons, among others, San Francisco has directed its employees and officers not to assist the Federal government in enforcing federal immigration law, with limited exceptions.

You can read the full text of the suit here, and it further asserts that Trump's Sanctuary City order "strikes at the heart of established principles of federalism and violates the United States Constitution."

While three of the largest cities in the state of California — Los Angeles, San Francisco, and Sacramento — already have declared themselves Sanctuary Cities, legislation introduced in December by California Senate President Kevin de León would make all of California a sanctuary for undocumented immigrants who do not commit violent felonies. As CBS 5 reports, that legislation is getting its first public hearing today in Sacramento.

The Hill reports that the measure, dubbed the California Values Act, would "prohibit state and local law enforcement agencies from spending money to enforce federal immigration laws [and] would also ban immigration enforcement in state schools, health facilities and courthouses."

Upon introducing the bill in December, de León said, "We will not stand by and let the federal government use our state and local agencies to separate mothers from their children."

Update: Herrera issued a formal statement on the lawsuit saying, "The president’s executive order is not only unconstitutional, it’s un-American. That is why we must stand up and oppose it. We are a nation of immigrants and a land of laws. We must be the ‘guardians of our democracy’ that President Obama urged us all to be in his farewell address.”

Mayor Ed Lee issued a statement on the city lawsuit, saying, in part, "I commend City Attorney Herrera and his team for their swift action on this filing to protect our Sanctuary City. The misguided Executive Order makes our cities less safe, and we believe, is unconstitutional."

Previously: 'A Sanctuary From Trump's Hate': San Francisco Reacts To Executive Order Punishing Sanctuary Cities