AUSTIN, Texas -

State senators are trading barbs as the chamber's Education Committee debates a high-profile school voucher bill.

Dan Patrick chairs the committee. His Senate Bill 23 offers tax credits to businesses that establish scholarships to help low-income students leave poor-performing public schools for private or religious ones.

It would let firms write-off all of their business margin taxes, but caps the total value of scholarships at $100 million.

Patrick said Tuesday that could help 10,000 students change schools.

But the Houston Republican spared frequently with Sen. Wendy Davis, a Fort Worth Democrat who said Texas shouldn't divert funds from cash-strapped public schools.

The bill has yet to reach the House. But lawmakers there have already voted overwhelmingly to keep public funding in public schools -- potentially threatening any major charter plan.