Four top voting-rights groups sent a letter to Texas officials blasting Attorney General Ken Paxton’s recently opened investigation into whether noncitizens in the state are being registered to vote. Paxton, a Republican, launched the probe this week based on a claim tweeted out by Fox News TV personality Maria Bartiromo, who claimed migrants were registering to vote outside a driver’s license office in North Texas’ Parker County. Bartiromo said she’d received the tip from “a friend,” who’d heard from a friend’s wife that people in a tent outside the office were illegally registering non-citizens.