tHE SPREAD of so-called sanctuary cities raises fair questions about how local law enforcement can balance collaboration with federal deportation officials, on the one hand, with maintaining trust with immigrant communities, on the other. Those questions were absent, however, when President Trump convened a roundtable on the issue the other day — a festival of scare-mongering, factual distortion and rhetorical overkill that did nothing to elucidate a tricky subject.

To hear the president tell it — along with a like-minded group of almost uniformly Republican officials, politicians and law enforcement — sanctuary cities are intent on unleashing a crime wave on America. They are doing so, Mr. Trump and his claque asserted, by safeguarding murderers, rapists and other bloodthirsty felons on what amounts to a virtual underground railroad traversed by illegal immigrants between local jails and vulnerable communities.

“We have gang members; we have predators, rapists, killers,” said the president. His assessment of sanctuary cities was seconded by a group that included Attorney General Jeff Sessions (“shocking,” “radical”); Rep. Michael McCaul (R-Tex.) (“they have blood on their hands”); Arkansas Attorney General Leslie Rutledge (“liberal cabals” fomenting “unconstitutional chaos”); and Sen. Patrick J. Toomey (R-Pa.) (“breed of madness”).

What hogwash.

The fact is that in virtually every so-called sanctuary jurisdiction, local officials continue to cooperate with federal deportation agents when it comes to handing over most dangerous and repeat offenders when their sentences are done; they do not do so in the case of minor offenders. Even in California — which, having recently enacted one of the nation’s most sweeping sanctuary laws, came in for special abuse at Mr. Trump’s event — local law enforcement is authorized to turn over unauthorized immigrants who have committed any of about 30 serious crimes to agents of U.S. Immigration and Customs Enforcement. And they can share information with ICE officials on inmates who have been convicted of hundreds more serious misdemeanors and felonies.

Those subtleties were swept under the carpet at the roundtable as officials vied with each other to scare Americans senseless. Texas Attorney General Ken Paxton said illegal immigrants had killed 1,200 people in the state since 2011. Actually, it’s fewer than half that many, according to the state’s own figures. (Mr. Paxton also said Texas had spent heavily on border security during his 12 years in the state legislature, ending in 2015, because the federal government “wouldn’t do it”; in fact, the number of Border Patrol officers along the Mexican border increased by more than 75 percent, to about 17,500, in that span.)

The event dovetailed with Mr. Trump’s ongoing crusade to use cherry-picked anecdotes to convince Americans that illegal immigrants pose a dire threat to law and order. Numerous studies have shown that immigrants, including undocumented immigrants, generally commit crimes at a lower rate than native-born Americans. The fact that those statistics clash with the president’s agenda doesn’t make them any less true.

Read more here: