President Donald Trump won largely on a platform of being tough on illegal immigration. He’s made several moves to keep his promises, but he’s often been stymied by the courts. Thursday was no different. The Seventh Circuit Court of Appeals in Chicago upheld a nationwide injunction against the Trump Justice Department’s plan to withhold money from sanctuary cities and the state of California.

One specific on which these cities and their Leftmedia propagandists — and now their judicial defenders — are deliberately dishonest is defining cooperation with federal authorities. Judge Ilana Rovner argued in her opinion that Attorney General Jeff Sessions overstepped his executive authority by using “the sword of federal funding to conscript state and local authorities to aid in federal civil immigration enforcement.” All three judges are Republican appointees, and it is indeed arguable that Trump’s mandate goes to far. But many of these cities aren’t merely objecting to being “conscripted,” as Rovner puts it; their laws forbid cooperation by local authorities. Trump obviously concluded that asking nicely wasn’t going to cut it.

For her part, Rovner made the issue one of separation of powers. “Our role in this case is not to assess the optimal immigration policies for our country,” Rovner writes. “Rather, the issue before us strikes at one of the bedrock principles of our nation, the protection of which transcends political party affiliation and rests at the heart of our system of government.

She explained, "The founders of our country well understood that the concentration of power threatens individual liberty and established a bulwark against such tyranny by creating a separation of powers among the branches of government. If the Executive Branch can determine policy, and then use the power of the purse to mandate compliance with that policy by the state and local governments, all without the authorization or even acquiescence of elected legislators, that check against tyranny is forsaken. … Congress repeatedly refused to approve of measures that would tie funding to state and local immigration policies. Nor … did Congress authorize the Attorney General to impose such conditions. It falls to us, the judiciary, as the remaining branch of the government, to act as a check on such usurpation of power. We are a country that jealously guards the separation of powers, and we must be ever‐vigilant in that endeavor.”

The bottom line is that sanctuary cities compromise the Rule of Law. Trump and Sessions are trying to restore that Rule of Law on immigration, but it’s an uphill battle.