At least 5 million voters, predominantly young and from minority groups sympathetic to President Barack Obama, could be affected by an unprecedented flurry of new legislation by Republican governors and GOP-led legislatures to change or restrict voting rights by Election Day 2012. Supporters of these new laws — spearheaded in six swing states, as well as other less competitive ones — argue they are just trying to stop voter fraud and protect the integrity of the vote. But opponents, mainly Democrats and Obama’s campaign, which is closely monitoring the daily warfare over the new laws, believe they are trying to change the face of the electorate in a way that benefits the Republican candidate for president. Pennsylvania, New Hampshire, Virginia and Wisconsin, all viewed as important states this fall, each have enacted stricter ID laws. Florida and Ohio have cut back on early voting. And a whole host of other states have passed new ID laws as well. As a result, millions of voters will find it much more difficult to vote on Election Day in November — some estimates, such as one from the Brennan Center of Justice last fall, put the number of those affected nationwide at more than 5 million. In Pennsylvania alone, the state’s Transportation Department released figures showing that more than 750,000 registered voters in the state — 9.2 percent of voters there — do not have the required forms of ID to vote in November.