Sen. Don Huffines is passionate about giving public school students the choice to attend private schools.

But he's raising eyebrows because of the combative tone he used Monday in Austin during a discussion about education at Texas PTA Rally Day with a group of students from Richardson ISD.

During one exchange, a student pushed back against a proposal to give students a stipend to attend private schools. She said, as other critics contend, that the voucher would not be large enough to allow the student to go to many high-dollar schools in North Texas.

"It won't work," she said.

Huffines countered by asking: "Do you want me to give them $15,000 so they can go to Hockaday or St. Mark's? That's the most selfish thing I've ever heard."

The Republican senator made the same point at a debate last week with state Rep. Rafael Anchia sponsored by The Texas Tribune, but he appeared more agitated during the discussion with Richardson students, who were in seventh grade and up.

A spokesman for Huffines said the senator acknowledged his tone was off.

"While the policy was right, Senator Huffines' tone and delivery today did not live up to the level of civil discourse that he always expects of himself and others," said Matt Langston, a spokesman for Huffines. "Senator Huffines is unapologetic in his support for education choice, because it's a policy that supports students. He will not hide from passionate or heated debate on the issue."

Langston then compared the meeting to an "ambush."

"Where other politicians might have run, Don Huffines stayed and endured the ambush-style attack, then calmly answered more questions for 15 more minutes, including questions from students," he said.

But Meredyth Childress, a PTA member and mother of one of the students at the meeting, said the students were not political operatives looking to "ambush" Huffines. They were given articles to review about private school vouchers before meeting with the senator. "We're very proud of the students," Childress said. "Both sides were passionate. One side displayed the proper respect and decorum. One side did not."

During one heated exchange, a woman told Huffines that it wasn't right to send money to private schools that was meant to help public schools.

"What makes you think it's your money?" Huffines responded, adding that businesses were taxpayers. "Sixty-two percent of all taxes are paid by businesses," he said.

At one point, Huffines barked at the group: "What are you all afraid of?"

Richardson ISD Superintendent Jeannie Stone said she was proud of how the students responded and grateful they attended the event with her and the PTA.

"My disappointment in Senator Huffines' comments is only exceeded by my pride in our students, who showed Austin how well public school students are prepared for life after high school," Stone said in a prepared statement. "They were poised and ready for a fact-based conversation about some of the most pressing issues facing Texas today."

Later Monday, Rep. Jason Villalba, R-Dallas, tweeted a photo of him with the Richardson group and said Huffines "ruined their day."

Huffines and Villalba have a contentious history. Before last March's primary, Villalba complained that Huffines helped his opponent try to unseat him, paying $150,000 for mailers that injected race into the campaign.

Democrats were also quick to criticize Huffines, who was elected in 2014.

"Nowhere in the job description of a Texas senator does it say to be disrespectful and rude to Texas students and their concerned parents who are demanding their fair shot to get ahead," said Manny Garcia, deputy executive director of the Texas Democratic Party. "Instead of investing in our children and economy, Republicans have voted over and over against a stronger future for all.

"Senator Huffines, remember who you work for. Shame on you. Stop yelling at children and do your job."

Staff writer Julie Fancher contributed to this report.