Wink-wink. Nudge-nudge.

One rule that I was taught early as a peace officer writing probable cause affidavits is the Four Corners Doctrine. Simply put, if the information is not put within the four corners of the sheet[s] of paper that the affidavit is written upon, the judge may not consider it.  If I charge Mr. Smith with Assault Causes Bodily Injury With Prior Conviction, I had darned well better mention his prior conviction for Assault CBI in that PC affidavit. I know of a judge who fairly recently threw out a PC on this doctrine, when the officer charged the defendant with Dischage Firearm In Certain Municipalities, but forgot to mention that the city was over 100,000 people. (Everyone knew that town had over 100,000 people, but the officer didn't mention it.)
It makes sense, though-- if it hasn't been testified to, the judge may not consider it.

Looking at the Arizona law SB1070 (which empowered Arizona law enforcement to make on-view warrantless arrests of individuals where there illegally, for violation of the new state law against being in Arizona illegally), we see that, first shake out of the box, it forbade enforcement based on ethnicity or race in black letter law. Yet concerns about harassment of people based upon race and ethnicity were exactly what got its opponents upset. A cynical person might also say that some were concerned that, even without harrassment based on race or ethnicity, some opponents were simply concerned that the law might actually be effective, in detaining and eventually deporting people not legally in this country.
But when the feds challenged the state law and brought it to the Supreme Court of this nation, the racial/ethnic issue wasn't brought up.

Although some critics of the law have contended that it would inevitably lead to targeting of Latinos simply because of appearance, speaking Spanish, or having a Spanish accent, Verrilli told the justices on April 25 “We're not making any allegation about racial or ethnic profiling in the case."

When the federal attorneys challenging a state enforcement law bring no allegation about race or ethnic oppression to court, that's because they haven't got any evidence supporting that issue.

But the law was struck down in all ways but one: state-appointed police are still permitted to enforce the federal immigration laws. The new provisions that it be illegal on a state level to seek work as an undocumented alien, and that that aliens must register with the state, and that Arizona law enforcement may make warrantless arrests of undocumented aliens for violation of the state law-- these were struck down.

The reasoning given by Justices Kennedy, Roberts, Ginsburg, Breyer and Sotomayor, was that the state must not usurp the federal authority. We already have laws about that. Huh. We have federal laws about drugs, and bank robbery, and a thousands of other things that are redundant on the state level. But this one, we must see overturned. But it's not about race or ethnicity.

The dissent given by Thomas and Scalia and Alito (all notably conservative or libertarian justices) is that there is state sovereingty to consider. The Arizona governor strangely claimed this as a victory for the 10th Amendment.

But it's not about race or ethnicity.