Buoyed by what they see as their best opportunity in a decade, education activists are spending millions of dollars and countless hours trying to persuade or pressure Pennsylvania lawmakers to approve school tuition vouchers.

From Pittsburgh to Harrisburg to Montgomery County to West Philadelphia, the money is paying for lobbyists, renting rally buses, printing pamphlets, even buying bright red backpacks for pupils.

It has flowed - sometimes in five- and six-figure checks - to legislators' campaign coffers. And it has funded an unusual wave of attack ads, mailers, and websites against lawmakers who are undecided or opposed to vouchers.

The effort reflects hopes that stretch beyond Pennsylvania. New Jersey Gov. Christie has made vouchers part of his education budget proposal now pending in Trenton.

Last year's elections gave tuition-voucher proponents the upper hand in many state capitals, including Harrisburg. Vouchers are part of a school-reform bill signed Thursday by Indiana Gov. Mitch Daniels. Officials in Florida, Ohio, and Louisiana are weighing bills to create or expand vouchers.

"This is a hugely important year for the movement," said Andrew Campanella, a spokesman for the American Federation for Children in Washington, which gave $1.2 million last fall to a political action group funding Pennsylvania candidates. He said the state "is certainly one of the top battlegrounds."

On Monday, Gov. Corbett is to deliver a keynote speech at the federation's national summit in Washington. Christie was a featured speaker last year.

The Pennsylvania proposal, introduced as Senate Bill 1, would give public-school students thousands of dollars for private tuition. The subsidy, with a price of at least $500 million, was originally limited to poor students in underperforming schools but has been expanded to some middle-income students.

The amount of each "opportunity scholarship" varies among districts depending on enrollment and other factors. Philadelphia students, for instance, could be eligible for about $7,500 a year.

The bill could be called up for a vote in the Republican-controlled Senate at any time. But the fine print remains unsettled. Once considered a slam-dunk by Corbett and GOP leaders, the bill has been stalled recently by rural senators worried that it would give Philadelphia too much money while doing little for their districts.

The delay - and the prospect of victory - has pushed supporters into overdrive. They say vouchers will give deserving students a chance at a better education and stir competition that will force public schools to address their failings. Many see vouchers as a steppingstone to wider education reform.

"We think we have momentum," said Brendan Steinhauser, an organizer for FreedomWorks, a Washington advocacy group. "We want to carry through."

Critics such as the Pennsylvania State Education Association - the union that represents 191,000 teachers and staff - the NAACP, and the American Civil Liberties Union argue that a voucher program is tantamount to abandoning the neediest students and neighborhoods and could violate the U.S. Constitution separation of church and state.

They say Senate Bill 1 could divert as much as $1 billion over three years to private entities at a time when public schools already face devastating budget cuts.

"It doesn't make sense to cut public schools by $1.2 billion because you say you can't afford it - and propose to spend $500 million on tuition vouchers for private schools," PSEA spokesman David Broderic said.

For years, the pro-voucher movement was dominated by conservatives, Republicans, and wealthy business leaders. But the issue now draws support from across the political spectrum.

The American Federation of Children, for instance, says Democrats received 40 percent of the $3 million it gave to candidates last year.

Its board of directors includes Carrie Walton Penner, whose family founded Wal-Mart; and Betsy DeVos, former head of the Michigan Republican Party; but also Boykin Curry, cofounder of Democrats for Education Reform; and Democrat Kevin Chavous, a former Washington, D.C., councilman.

On Tuesday, both sides staged dueling rallies in Harrisburg. Unionized teachers and their supporters filled the front of the Capitol, and Joann Carraway gathered with hundreds of students, parents, and other voucher allies in the back.

"I want my child to have the best education she can get and I've been on both sides," said Carraway, who went on a bus organized by the Roman Catholic Diocese of Pittsburgh.

Carraway said she moved her daughter Jennifer to a Catholic school in fourth grade to escape a violence-plagued neighborhood public school. Now she has to send her back. "I'd like her to go to Catholic school, but we can't afford it," she said.

The rally that drew her to Harrisburg was organized in part by FreedomWorks; dozens of children there sported bright red backpacks emblazoned with the group's logo.

FreedomWorks has "easily" spent hundreds of thousands of dollars promoting Senate Bill 1 through rallies and workshops from Wilkes-Barre to Pittsburgh, Steinhauser said. In March, the group's chairman, former U.S. House Majority Leader Dick Armey, went to Harrisburg to talk to legislators.

Its campaign includes broadsides aimed at voucher opponents. Two radio ads, for instance, accuse Republican State Sens. Stewart Greenleaf of Montgomery County and Lisa Baker of Luzerne County of "pandering to the teachers union" for not supporting the bill.

"The gloves are off," Steinhauser said.

In addition, the Commonwealth Foundation, a Harrisburg think tank, launched www.standstrongsenator.com to target six legislators who oppose the bill or are undecided. One was Sen. Pat Vance (R., Cumberland), who voted against vouchers in a committee vote. "This is over the edge, and it doesn't change my mind," she said.

And last week, State Sen. Daylin Leach (D., Montgomery) urged colleagues to decry the tactics after his constituents received a mailer claiming the senator "refuses to help kids trapped in violent schools." In his letter to lawmakers, Leach assailed the card as a "nasty" and dishonest smear by "rich bullies."

"This is campaign-style mail with personal attacks 17 months out from an election," he said in an interview. "That 'I hate kids' is beyond the pale and despicable."

Some longtime political observers said the tactics were unusual but not surprising given the wide interest in the outcome here.

"That's standard operating procedure at the national level and underscores the amount of money at stake here," said Tony May, a lobbyist who was a consultant to the teachers union when vouchers were first proposed in the mid-1990s.

The Leach mailer - and a similar one that went to constituents of Rep. James Roebuck (D., Phila.) - were produced by the Pennsylvania chapter of Students First, a national group leading the charge and bankrolling the effort here.

In October, the American Federation of Children sent the group three checks totaling $1.2 million, records show.

In the weeks that followed, Students First gave at least $957,000 to legislative candidates and political committees. Nearly half went to the campaigns of 14 state senators. In January, those same lawmakers - 11 Republicans and three Democrats - became primary sponsors of Senate Bill 1.

The biggest checks - $100,000 each - went to the two most-powerful Republicans in the Senate, President Pro Tempore Joseph Scarnati (R., Jefferson) and Majority Leader Dominic Pileggi (R., Delaware), and to Sen. Anthony H. Williams, the Philadelphia Democrat who has been a longtime supporter of vouchers.

Williams raised eyebrows statewide last year with an 11th-hour bid for governor with $5 million bankrolled through Students First and a trio of Bala Cynwyd multimillionaire investors who are ardent advocates of school reform, including vouchers.

(Corbett later named one of those businessmen, Joel Greenberg, co-chair of his education transition team.)

Students First also spent $157,000 to lobby Harrisburg in the first quarter of this year. And late last month, it reported hiring Stephen Wodjak and Rocco Pugliese, two influential lobbyists, especially with Democrats.

"It's important for us to win legislators to our side," said Joe Watkins, chairman of Students First-PA and formerly a White House aide under George H.W. Bush. "Any legislator can change his or her mind. We'd like to change as many as we can."

Chris Bravacos, a lobbyist and board president of the Reach Alliance, which for 20 years has pressed for school-choice legislation, said the resources of a group like Students First were refreshing.

"I don't think there's any question that they've been able to somewhat level the playing field that had otherwise been tilted toward the teachers union," he said.

Last year, the PSEA and its political action committee gave $1.9 million in campaign contributions, records show. The money went to both sides of the voucher debate, but the biggest checks went to Democrats opposed to vouchers.

In New Jersey, the teachers union last year spent more than $6.6 million on lobbying, trying to fend off widespread budget cuts and an ongoing assault from its new governor. Among registered lobbyists, the next-biggest spender, at $458,000, was a pro-voucher group, Excellent Education for Everyone, state records show.

Vouchers are just one of the school changes Christie is pushing. His proposed Opportunity Scholarship Act would give corporations tax credits for funding vouchers for children in underperforming districts, similar to an existing program in Pennsylvania.

Broderic, the PSEA spokesman, said his union was increasing its spending on lobbying and issue advocacy in Harrisburg, though he said he did not have details. "Certainly, the nature of the challenges have required us to engage like we never have engaged before, and that takes resources and time," he said.

Watkins, of Students First-PA, said the effort wouldn't end even if Senate Bill 1 passes. The same groups intend to press for charter-school funding, merit pay for teachers, and other changes.

"There's so much more to be done," he said.