Embattled FBI agent Peter Strzok suggested during an open hearing Thursday that the ongoing congressional investigation into political bias within the FBI would severely damage the institution of American law enforcement. “This entire exercise comes at a cost,” said Strzok, who was removed from Special Counsel Robert Mueller’s probe of Russian interference in the 2016 presidential election. “We are doing things that are going to, in the future, tear down the underpinnings of what represents law and order in this country. And there is not a robust, thick wall there. I think people don’t appreciate how tenuous the balance of...