March 23, 2011 -- An Arizona state senator has set off a hot debate over racism and taxpayer-funded education of illegal immigrants with her public reading of a constituent letter that said most Hispanic students "hate America."

"Most of the Hispanic students do not want to be educated but rather be gang members and gangsters," said State Sen. Lori Klein on the chamber floor Friday, quoting from a letter by a Phoenix-area substitute public school teacher sent to Senate President Russell Pearce. "They hate America and are determined to reclaim this area for Mexico."

Klein, a Republican, was speaking in support of a bill which would require the Arizona Department of Education to collect data on students who cannot prove their "lawful residence" in the U.S. in order to better estimate the cost of educating illegal immigrants.

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"If we are able to remove the illegals out of our schools, the class sizes would be reduced and the students who wanted to learn would have a better chance to do so and become productive citizens," Klein continued, quoting from the teacher's letter without revealing his identity. "Thank you for standing up to this invasion."

The presentation drew an impassioned rebuke from Democratic State Sen. Steve Gallardo, who questioned the authenticity of the anonymous letter, and called the reading of it into the public record deplorable.

"I don't think I've ever heard any floor speech similar to the one that was given out right now," Gallardo said. These students "do not have dreams to be gang members, they do not want to be thugs or whatever we want to phrase it as. These are good kids."

The bill "does one thing. It puts fear in our communities and our schools. That's all it does," he said. Minutes later the measure passed a procedural vote.

The teacher behind the letter, Tony Hill, came forward Monday to confirm details of his experience teaching Hispanic students in an interview with the Arizona Republic.

Hill said he wrote state legislators after substitute teaching in a suburban-Phoenix public school where most of his 8th grade students were undocumented, and made offensive statements about the U.S.

"It just upset me that this was what's occurring," he told the Republic, "to see this disregard for America and their hatred towards it and their entitlement."

Teacher Sparks Outrage in Ariz.

While immigrant advocates and civil rights groups have protested the bill itself, the most outrage was sparked by the reading of the letter.

"I've seen a lot of things like this, it's not that out of the ordinary," Anti-Defamation League regional director Bill Straus said in an interview about the letter with local ABC affiliate KNXV. "What is out of the orginary is that it gets the credibility of a state senator reading it word for word on the floor of the senate. It's a disgrace."

Klein said the letter does not reflect her personal view and was not intended to offend. She said she wanted to use it to illustrate one example of conditions inside Phoenix schools.

"Not one of us on the Senate floor is racist or has anything other than the hope that people who are here in this country will appreciate what they are getting in terms of their education to get ahead in life," she told KNXV.

The Supreme Court ruled in a landmark decision in 1982 that primary and secondary school students cannot be denied an education in the U.S. based on their immigration status.

An estimated 65,000 undocumented immigrants graduate from U.S. public high schools every year, according to the Urban Institute.

ABC News local affiliate KNXV contributed to this report.