YAKIMA, Wash. (AP) - Republican Rob McKenna and Democrat Jay Inslee sparred over taxes, immigration and health insurance Tuesday in the third debate of their tight race for governor. Recent polls show Inslee has opened a slight lead in this Democratic-leaning state. Both candidates are seeking to replace Democrat Chris Gregoire, who did not seek a third term. The debate at the Yakima Convention Center showed a sharp difference between the candidates over a federal plan to expand Medicaid in the state to cover more people without health insurance. McKenna said he was opposed to the proposal, because the federal government will pay the costs only for the first three years. He said the proposal would prompt thousands of people to drop private insurance and enroll in Medicaid. But Inslee called it a "no-brainer" that he supported. He said Washington residents already pay the medical costs of uninsured people who show up at hospitals.