WASHINGTON (AP) — State funding for pre-kindergarten programs had its largest drop ever last year and states are now spending less per child than they did a decade ago, according to a report released Monday.

The report also found that more than a half million of those preschool students are in programs that don't even meet standards suggested by industry experts that would qualify for federal dollars.

Those findings — combined with Congress' reluctance to spend new dollars — complicate President Barack Obama's effort to expand pre-K programs across the country. While Education Secretary Arne Duncan and Health and Human Services Secretary Kathleen Sebelius continue to promote the president's proposal, researchers say existing programs are inadequate, and until their shortcomings are fixed there is little desire by lawmakers to get behind Obama's call for more preschool.

"The state of preschool was a state of emergency," said Steven Barnett, director of the National Institute for Early Education Research at Rutgers University, which produced the report.

During his State of the Union speech, Obama proposed a federal-state partnership that would dramatically expand options for families with young children. Obama's plan would fund public preschool for any 4-year-old whose family income was below twice the federal poverty rate.

If it were in place this year, the plan would allow a family of four with two children to enroll students in a pre-K program if the family earned less than $46,566.

Students from families who earn more could participate in the program, but their parents would have to pay tuition based on their income. Eventually, 3-year-old students would be part of the program, too.

As part of his budget request, Obama proposed spending $75 billion over 10 years to help states get these new programs up and running. During the first years, Washington would pick up the majority of the cost before shifting costs to states.

"It's the most significant opportunity to expand access to pre-K that this nation has ever seen," Barnett said of the president's proposal.

Obama proposed paying for this expansion by almost doubling the federal tax on cigarettes, to $1.95 per pack.

Obama's pre-K plan faces a tough uphill climb, though, with the tobacco industry opposing the tax that would pay for it and lawmakers from tobacco-producing states also skeptical. Conservative lawmakers have balked at starting another government program, as well. Obama's Democratic allies are clamoring to make it a priority.

To help it along, Duncan and Sebelius planned to join the report's researchers on Monday at a news conference to introduce the report, along with administration allies. They planned events later in the week to reiterate their support.

Yet those public events were unlikely to sway lawmakers who are already fighting among themselves over spending cuts that are forcing students to be dropped from existing preschool programs, the levying of higher fees for student loans and deep cuts for aid to military schools.

States spent about $5.1 billion on pre-K programs in 2011-12, the most recent school year, researchers wrote in the report.

Per-student funding for existing programs during that year dropped to an average of $3,841 for each student. It was the first time average spending per student dropped below $4,000 in today's dollars since researchers started tracking it during the 2001-02 academic year.

Adjusted for inflation, per-student funding has been cut by more than $1,000 during the last decade.

Yet nationwide, the amounts were widely varied. The District of Columbia spent almost $14,000 on every child in its program while the states of Colorado, South Carolina and Nebraska spent less than $2,000 per child.

"Whether you get a quality preschool program does depend on what ZIP code you are in," Barnett said.

Among the 40 states that offer state-funded pre-K programs, 27 cut per-student spending last year. In total, that meant $548 million in cuts.

Money, of course, is not a guarantee for students' success. But students from poor schools generally lag students from better-funded counterparts and those students from impoverished families arrive in kindergarten less prepared than others.

In all, only 15 states and the District of Columbia spent enough money to provide quality programs, the researchers concluded. Those programs serve about 20 percent of the 1.3 million enrolled in state-funded prekindergarten programs.

"In far too many states, funding levels have fallen so low as to bring into question the effectiveness of their programs by any reasonable standard," researchers wrote.

Part of the reason for the decreased spending are the lingering effects of the economic downturn in 2008, coupled with the end of federal stimulus dollars to plug state budgets.

"Although the recession is technically over, the recovery in state revenues has lagged the recovery of the general economy and has been slower and weaker than following prior recessions. This does not bode well for digging back out of the hole created by years of cuts," the researchers wrote in their report.

Nationally, 42 percent of students — or more than a half million students — were in programs that met fewer than half of the benchmarks researchers identified as important to gauging a program's effectiveness, such as classrooms with fewer than 20 students and teachers with bachelor's degrees.

That, too, suggests problems for Obama's plan to expand pre-K programs, especially if Washington insists its partners meet quality benchmarks to win federal dollars.