right-wing groups want court to let them sue the irs in a class-action lawsuit for violating their constitutional right to equal treatment .
irs applied different criteria to right-wing groups , holding up their applications for years while liberal organizations skated through .
obama administration fought the release of a list of 298 groups it denied tax-exempt status beginning in 2010 , citing privacy concerns .
judge in cincinnati overruled the government and ordered the irs to hand over the list .
if court ` certifies ' class-action status , the tea party groups will be free to demand emails , phone records and other documents .