Attorneys are warning that a recent court ruling could make it harder for lenders to invoke federal preemption to fend off state efforts to rein in abusive lending and restrict the business of subprime lenders. In a ruling favoring state regulators, a federal district court in Illinois found that the Home Ownership and Equity Protection Act, rather than the Alternative Mortgage Transaction Parity Act, should be the law to analyze for questions of federal preemption.