Six states engaged in litigation over an Obamacare tax on Medicaid plans filed papers this week asking a Texas federal judge to block the IRS from collecting that tax on Oct. 1. The states argue that federal regulations are illegally forcing the states to cover the cost of the tax by paying higher capitation rates to the managed-care companies that operate the states’ Medicaid programs. The so-called Health Insurance Providers Fee is an annual tax on health insurers enacted by...