Maryland Gov. Martin O’Malley (D) wants to expand access to pre-kindergarten classes to more 4-year-olds in the coming year and has set aside $4.3 million to cover the cost. But when lawmakers gathered Wednesday to discuss the legislative proposal, they largely focused on this question: When could the state afford to do even more?

Each of the three leading Democratic candidates vying to become the next governor has embraced expanding pre-kindergarten programs to put more 4-year-olds in the classroom.

One of those candidates, Lt. Gov. Anthony G. Brown (D), appeared before two General Assembly committees Wednesday and spoke about the importance of quality early childhood education in reducing gaps in knowledge and achievement between low-income or minority students and their more affluent classmates.

Children who are exposed to pre-kindergarten classes start kindergarten with more than twice as many words in their vocabulary, he said, setting them on track for years of academic achievement. They are less likely to drop out of school, need special education or have to repeat a grade.

“We know there are still too many children who don’t have access to quality pre-K,” Brown said to a panel of delegates. “These children are in danger of being left behind.”

Maryland public school systems are required to offer pre-kindergarten to economically disadvantaged or homeless 4-year-olds. To qualify, the child’s family must make less than 185 percent of the federal government’s definition of poverty. For a single parent, that would mean making about $28,693 or less. For a family of four, about $43,567 or less.

During the 2012-13 school year, more than 26,400 4-year-olds were enrolled.

The legislation sponsored by the O’Malley administration would provide grants to local school systems and pre-
kindergarten providers that want to accept children from families making 300 percent of the poverty rate. For a single parent, that would mean making up to $46,530. For a family of four, up to $70,650. Providers could also apply to expand some half-day programs to full day and, in some cases, offer care for up to 12 hours a day at designated centers.

State officials hope that the funding will help an additional 1,600 children across the state.

Brown said that the legislation is one step toward the ultimate goal of providing pre-kindergarten to all 4-year-olds, regardless of income. That effort would probably cost $120 million to $140 million a year, he said. Brown’s campaign has said that the expansion, which would be phased in until 2018, would probably be paid for by proceeds from Maryland’s gambling revenues.

Del. Heather R. Mizeur (D-Montgomery), who also is seeking to become the state’s next governor, has proposed phasing in full-day pre-K programs for all 4-year-olds and half-day programs for 3-year-olds from lower-income families. The cost of the initiative, once fully implemented, would be close to $280 million a year. She suggests that Maryland legalize marijuana and use the tax revenue it generates to fund pre-kindergarten education.

And Attorney General Douglas F. Gansler (D) has pledged to expand the state’s pre-kindergarten offerings from half-day to full-day programs and increase the eligibility requirement to 300 percent of the poverty definition. Such an expansion would cost about $20 million a year and would be funded with gambling proceeds budgeted from the horse-racing industry.

Ahead of the Wednesday hearings, Brown’s campaign put out a statement — along with a link to an online video — that criticized Gansler for not embracing pre-kindergarten for all 4-year-olds. Gansler has said that such plans are not affordable.

Del. Jolene Ivey (D-Prince George’s), Gansler’s running mate, said during the hearing that the proposed expansion for the upcoming year has too little funding to make a serious impact.

“We all agree that pre-K is really, really helpful in getting kids up to speed and ready to learn,” Ivey said. “This is a nice symbol, but $4 million just isn’t going to do much.”