Republican Rick Scott launched a new TV ad Tuesday ridiculing Democratic rival Alex Sink’s past support of tax increases, labeling her a “liberal” who backs higher taxes “morning, noon and night.”But the centerpiece of Scott’s own tax-cutting plan, elimination of the state’s corporate income tax, is drawing pushback from some on both the political left and right, who warn it will drain needed state dollars even as it jeopardizes a longstanding private-school voucher program.“We’re hoping that if he becomes governor, some people in his own party will see that this idea could cause some real collateral damage,” said Jon East, a spokesman for the Florida School Choice Fund, an advocate for the state’s school voucher program, which this year will draw as much as $140 million in business tax credits for sending low-income students to private schools.The corporate income tax is by far the largest funding source for the program, which helped pay tuition and fees for almost 29,000 students in private and parochial schools.