Even as education became a theme at the Republican National Convention, it was clear the policy lines between the parties are murkier than on many other issues.

New Jersey Gov. Chris Christie used his keynote address Tuesday evening to take a swipe at Democrats over their support for teachers’ unions, even though he has successfully negotiated with them in his home state.

“They believe the educational savages will only put themselves ahead of children, that self-interest will always trump common sense, they believe in pitting unions against teachers, educators against parents, lobbyists against children,” Christie said. “They believe in teachers’ unions. “We believe in teachers.”

Randi Weingarten, the head of the American Federation of Teachers, was quick to say in response that Christie did negotiate an overhaul of education policy.

“Gov. Christie, just three weeks ago . gave the teachers’ unions tremendous credit,” Weingarten said in an interview.

Progress on national education policy has stalled. The Elementary and Secondary Education Act, most recently known as No Child Left Behind, technically expired in 2007. Despite work in Congress and proposals from the White House, the reauthorization is on a laundry list of measures that lawmakers have no intention of addressing.

That’s led the Obama administration to grant states waivers for some of the more onerous requirements of NCLB.

Speaking Thursday at a panel discussion held in conjunction with the convention, House Majority Leader Eric Cantor (R-Va.) said he thought the waivers addressed some local “angst” with the law.

“What that has done, though, is, I believe, put in place substitution of Obama standards for what was in the statute originally, instead of what I believe Mitt Romney is talking about, which is to give much more flexibility to the local level school districts, to the parents, to begin to empower them to use this information that came from NCLB,” Cantor said at a forum sponsored by Bloomberg and the Tampa Bay Host Committee.

In granting the waivers, though, the administration is in several instances responding to the requests of local districts and jurisdictions that span the political spectrum.

The teachers’ unions argue that instead of flexibility and local control, Cantor, Romney and other Republicans really want to undermine not just the unions, but spending on K-12 education more broadly.

“The only strategy they have raised is the one that actually doubles down on disinvestment in public school,” Weingarten said in reference to the GOP push for block grants of education and school vouchers.

Weingarten called the criticism of unions “a smokescreen for divesting from education” that is “is really a disservice to the American people.”

Weingarten says this differs from Democrats, even those who have criticized the unions at the local level.

As attention turns to the Democrats’ gathering in Charlotte, N.C., for their own convention next week, the education debate will be somewhat less predictable. Many Democratic mayors have had standoffs with teachers unions over contracts on matters ranging from tenure to the length of the school day.

Advocates of overhauling the public education system on the Democratic side have had vociferous disagreements with unions, with the most obvious example being Washington, D.C., where former Chancellor Michelle Rhee had regular disputes with Weingarten.

“Democratic advocates of education reform are fighting for the fundamental civil right of all children to have a high quality education – a right that is currently being denied to too many children, especially those of color and from low-income communities,” said Hari Sevugan, vice president for communications with StudentsFirst, an education advocacy organization founded by Rhee.

“Every time our party defends a broken public institution, we hurt our ability to argue that government can be an instrument of change. Unfortunately, that’s the case too often when we are talking about schools, and for the sake of the country and the party, that needs to change,” Sevugan added. He was previously a national spokesman for the Democratic National Committee and the 2008 Obama campaign.

Sevugan highlighted that many Democratic mayors have backed a “parent-trigger” that would allow parents in failing schools to launch petition drives to change the structure of the school, which could in some cases result in the conversion to charter schools.

StudentsFirst held a film screening in Tampa of the film “Don’t Back Down,” which tells a story about an effort to overhaul an underperforming inner city school. The group will do the same in Charlotte next week.

Los Angeles Mayor Antonio Villaraigosa, who is also the chairman of the Democratic National Convention, is among those supporting a related resolution by the U.S. Conference of Mayors.

Villaraigosa is not alone. The union in Chicago filed a 10-day strike notice earlier this week amid a contract dispute with Mayor Rahm Emanuel, the fiery former Congressman who was President Barack Obama’s White House chief of staff.

Weingarten emphasized that issue is different from the GOP-led efforts.

“We have urged both parties to stay at the table until they have resolved these issues,” she said.