Argument #1
The Court should rule with the government (Sullivan) in these cases. The government has no constitutional duty to subsidize an activity because it is constitutionally protected, be it free speech or privacy. Employees who work for the government are limited in their freedom of expression while they are working on a federally financed project.
Argument #2
The Court should rule with Rust and New York in these cases. The regulations that are contained in these laws are viewpoint-based restrictions and they therefore violate free speech values.