Moments after President Obama rolled out a sweeping overhaul proposal for corporate taxes -- wiping out many deductions while reducing the corporate tax rate -- Republican primary contender Mitt Romney introduced tax reductions of his own. The Romney proposal calls for a 20 percent reduction in marginal rates for personal income tax -- which would reduce taxes across all brackets. The differences between the two plans reflect the divergent approaches to taxes underlying their election campaigns. Obama has chosen not to pursue changes in income tax rates, and instead wants to eliminate tax breaks, deductions, and special strategies that allow many American companies to dramatically discount the amount of taxes they pay.