WASHINGTON -- Illinois public employee unions struck back Thursday, filing a lawsuit to block Gov. Bruce Rauner's attempt to prevent them from collecting certain mandatory fees from workers. Twenty-seven unions, representing more than 40,000 state employees, are challenging an executive order from the Republican governor aimed at so-called fair-share fees. In Illinois, public employees who are not union members must pay these fees, in lieu of dues, to cover the costs of collective bargaining that benefits them.