"There will be a lot of county officials who are impressed that early childhood education is a worthwhile priority, and at the same time distressed at how you find the resources to get from here to there," he said.

For that reason, Gansler and Brown say that while the long-term goal would be to give every Maryland 4-year-old the ability to start public school a year early, in reality providing pre-K would mean funding a combination of private and public programs.

Gansler said that ideally, "instead of having K through 6, you'd have pre-K through 6. That's not, in the very near term, plausible or possible."

Brown has suggested making half-day programs available to all Maryland 4-year-olds by 2019, a plan he estimates will cost $153 million annually and includes $10 million a year to help with construction costs.

Brown's expansion would be a mix of public and private pre-K providers, said campaign manager Justin Shall. While the idea would be to eventually put full-day pre-K programs in every public school, "That's a solution that will take 20 to 25 years," Shall said.

Details released so far by Mizeur's campaign suggest her plan would go further than the others, granting state-funded pre-K to all Maryland 4-year-olds and to 3-year-olds from disadvantaged families.

Michael J. Martirano, superintendent of St. Mary's County public schools and chair of the Public Superintendents Association of Maryland, backs that approach.

"I'm going to promote universal, all-day pre-K for all young people. That's the ultimate gold-star program," Martirano said.

But, he added, "It's got to come along with the resources. That has an incredible price tag."