Supreme Court and the First Amendment

The Supreme Court has accepted for decision a case which raises the right of public employees to refrain from paying any union dues, even for essentially non-political union activities such as collective bargaining and contract administration, from which they directly benefit. The objectors are non-union employees who oppose the political activities and/or contributions of the union, yet accept wage increases won by the union for all employees.
The case is part of a campaign to destroy public employee unions. Given the philosophic make up of the current court, the result is a foregone conclusion but the underlying rationale is deeply troubling. Apparently, the conservative majority elevates certain First Amendment protections over others, depending upon whose ox is being gored.
If Americans have a First Amendment right to object to being compelled to contribute to causes they abhor, why must they pay that portion of their taxes earmarked for war materiel or nuclear arms production? If they are not entitled to a corresponding tax reduction, they should, at the least, be permitted to require that their payments be allocated to governmental services they support.
Similarly, corporate shareholders should have the constitutional right to be compensated to the extent that the value of their shares are diminished by contributions made by the corporation to political action committees who support candidates or causes anathema to the shareholder. Taxpayers and shareholders are no less entitled to First Amendment protection than are non-union workers.