Ask Antonio White what he thinks of Race to the Top--President Barack Obama's signature K-12 initiative--and the Florida teacher will tell you the competitive-grant program is a "difficult pill to swallow." Merit pay for teachers based partly on student test scores is "a joke," he says. He's also not a fan of expanding charter schools, or of U.S. Secretary of Education Arne Duncan. Still, Mr. White, like thousands of educators around the country, has spent months making calls and knocking on doors, trying to persuade voters to support a president with whom he has sharp disagreements on a host of issues central to his profession. Though policy differences may have dampened enthusiasm for some, many teachers back President Obama for re-election.