AUSTIN — A battle at the Capitol over whether Texas should expand Medicaid is coming down to two competing philosophies. One, the likely winner, is pushed by Brenham Republican Rep. Lois Kolkhorst, chairwoman of the House Public Health Committee. She says the state should wait to gauge the effect of the other major provision that the Affordable Care Act uses to expand health coverage, a new insurance exchange. Kolkhorst argues that the exchange, a sort of Travelocity for health insurance, will solve much of the state's problem of lack of insurance coverage. Expanding Medicaid, she complains, would be wastefully expensive, even though the federal government would foot the entire bill, at least initially.