But his threat illustrated the heated rhetoric around the issue of the laws being passed around the country, taking such actions as strengthening requirements for voter ID. Democrats on the Senate Judiciary subcommittee on the Constitution pressed the highly charged attack that the state laws are racist and aimed to keep Black people from voting. They vowed to block them. “We cannot let these attacks on democracy stand,” Mr. Blumenthal said. Democrats are pushing for an update to the federal civil-rights voting law that would undo the U.S. Supreme Court’s decision in a 2013 case, Shelby County v. Holder. The ruling effectively took away a provision in the Voting Rights Act requiring states with a history of discrimination to get approval from the Justice Department to change elections laws or policies.