A surge in serious crimes by illegal immigrants—many repeat offenders—who have been shielded by sanctuary laws isn’t stopping legislators in Massachusetts from quietly pushing for a measure that would protect undocumented aliens statewide. The move could not have come at a worse time, as the nation reels from a series of atrocious crimes committed by illegal aliens who long ago should have been deported. Instead, they were protected by sanctuary laws despite their criminal histories and illegal status in the U.S. A recent example is the gruesome July 4 San Francisco murder of a young woman by an illegal immigrant...