Semi-Obvious Solution to Bidirectionality Problem
Can't you just limit bidirectionality within the resolution by specifying the direction the Aff must rule? For example....
The USSC should overrule one of the following:
Casey v. Planned Parenthood, in order to increase access to abortion
Gratz v. Bollinger, in order to increase the availability of affirmative action
Morrison, in order to permit a federal civil remedy for gendered violence
etc.
etc.