“It comes down to the old bugaboo, resources. It costs money to keep kids in school,” said Mayor Scott Smith of Mesa, Ariz. “Everyone believes we can achieve greater things if we have a longer school year. The question is, how do you pay for it?”

One model is Massachusetts, where the state issues grants to districts that set out clear plans on how they would use the money to constructively lengthen instructional class time, said Kathy Christie, chief of staff at ECS. Obama’s Education Department already is using competitions among states for curriculum grant money through its “Race to the Top” initiative.

“The federal carrots of additional money would help more states do it, or schools do it in states where they don’t have a state grant process,” Christie said.

But the federal budget is hard-up, too. And while many educators believe students would benefit from more high-quality learning time, the idea is not universally popular.

In Kansas, sporadic efforts by local districts to extend the school year at even a few schools have been met by parental resistance, said state education commissioner Diane DeBacker.

“It’s been tried,” she said, describing one instance of a Topeka-area elementary school that scrapped year-round schooling after just one year. “The community was just not ready for kids to be in school all summer long. Kids wanted to go swimming. Their families wanted to go on vacation.”

Teachers’ unions say they’re open to the discussion of longer classroom time, but they also say that pay needs to be part of the conversation. As for Obama’s call for ousting underperforming teachers, National Education Association President Dennis Van Roekel said unions weren’t the main stumbling block there, as many education reformers assert.

“No one wants an incompetent teacher in the classroom,” Van Roekel said. “It’s in the hiring, and in those first three to five years no teacher has the right to due process.”

In announcing his goal of recruiting 10,000 new STEM teachers over the next two years, Obama said: “Strengthening STEM education is vital to preparing our students to compete in the 21st-century economy, and we need to recruit and train math and science teachers to support our nation’s students.”

Obama didn’t specify how his administration plans to meet this goal, but in a separate announcement, Education Secretary Arne Duncan launched a national teacher recruitment campaign that could help in the effort. The campaign features a new web site, www.teach.gov, with information for students and prospective teachers—including a new interactive “pathway to teaching” tool designed to help individuals chart their course to becoming a teacher.