On Tuesday, voters in two states -- Washington and Georgia -- will be weighing in on charter schools.

Charter schools are independent public schools that have flexibility in certain aspects of education like curriculum and length of the school day. In return for this flexibility, they are held accountable for student performance.

The research is mixed on whether students in charters perform better than their traditional public school counterparts. Some cite the CREDO study from Stanford University, which found that "17 percent of charter schools provide superior education opportunities for their students." According to this study, about half the charters did not fare any better or worse than their traditional school counterparts, and about 37 percent of the charters fared worse.

Others cite research like that found in the "Informing the Debate" study from the Boston Foundation, which "found large positive effects for Charter Schools at both the middle and high school levels."

Currently, 41 states and the District of Columbia have charter schools.

The topic of charter schools, including how they are established and who gets to attend them, stirs up a lot of emotion among parents, educators and policymakers. Because it's relatively new territory, shaping legislation on charters has become a public tug-of-war. The states of Washington and Georgia have charter school initiatives on their ballots.

Washington's Initiative 1240

Washington has put ballot measures on charters in front of voters three times before, each one rejected -- most recently in 2004, when the measure failed by 16 percentage points. There are no charter schools in Washington.

The latest attempt is Initiative 1240, which would allow for the establishment of eight charter schools in the state per year -- 40 over five years. At the end of that period, the charter system would be up for review. The state-approved charter schools would be free and open to all students and be independently operated.

Washington is bound by its state constitution to fully fund education. In the tough economic times of the last three years, the state cut $2.5 billion from its education budget. Earlier this year, the Washington Supreme Court ruled that the state was underfunding its public schools so much that it was not meeting its constitutional obligation to educate each child. The state was ordered to comply with its constitutional mandate and not to make further cuts for fiscal reasons.

Critics of charters say this is a bad time for I-1240, that it is the wrong time for the state to embark on a new system of schools that they say will cost more money.

"Why would you add charters at a cost of millions of dollars at a time when we haven't fully funded what we have now?" asks Marianne Bichsel, communications director for People for Our Public Schools.

Bichsel said the organization's opposition to I-1240 is not about opposition to charter schools, it's about a "poorly written" measure that she said will at best serve less than 1 percent of Washington's students and families. She points out that the eight schools established each year will choose their students by lottery.

"This is the wrong approach at the wrong time," Bichsel said. "We need solutions to serve all students."

Supporters of I-1240 say that charter schools would offer parents choices and insert true competition into the educational space. The charter schools they envision would not be bound by district curriculum mandates and policies and not be subject to teachers unions' wishes.

Liv Finne, director for education at the Washington Policy Center, calls 1240 "a modest proposal" in that it would allow for only eight charter schools per year in a state that currently has more than 2,300 schools.

She and other charter advocates want a decentralized, accountable system of schools. Finne believes that I-1240 is one way to create that kind of system and bring parents alternatives to failing schools.

"For too long, Washington state has clung to an outmoded highly centralized system of delivering education, which the evidence shows fails to adequately educate far too many children," said Finne.

She points out that in the 41 states that have charters, they are popular with parents, the public and policymakers.

Bichsel said that I-1240 mandates that the charter schools would be run by independent charter operators and interests outside Washington. The initiative, she said, is being funded by wealthy individuals both inside and outside the state.

As of October 18, Bill Gates has donated more than $3 million to support I-1240, according to the Washington Post.

Microsoft billionaire Paul Allen of Seattle and Alice Walton of Wal-Mart founding family have also contributed, among others, according to state public disclosure records.

Supporters of the initiative, including Finne, point to the financial muscle of Washington state's teachers unions and approximately $33 million per year that is collected in union dues as the other side of the money trail. The unions are against the charter initiative.

Georgia's Amendment 1

In Georgia, 2,700 miles away, voters also have charters on their minds.