NEW ORLEANS — For the last two years, Democrats in battleground states have played defense against Republican efforts to curtail voting access and amplify doubts about the legitimacy of the nation’s elections. Now it is Democrats, who retained all but one of the governor’s offices they hold and won control of state legislatures in Michigan and Minnesota, who are ready to go on offense in 2023. They are putting forward a long list of proposals that include creating automatic voter registration systems, preregistering teenagers to vote before they turn 18, returning the franchise to felons released from prison and criminalizing...