–   No.  Not renewing P’s contract was not a violation of P’s First Am. rights because P’s speech to the radio station was not a substantial factor in his getting fired.  When there are mixed motives—speech and non-speech reasons for an employee being fired—then the following test will apply:  P must show that his constitutionally-protected speech was a “substantial factor” in his being terminated, and then the District Court must determine whether the Board had shown by a preponderance of the evidence that it would have reached the same decision as to P’s termination even in the
absence of the protected First Am. conduct.
1.    Although the Court remanded this case to the Tr. Ct. to apply
the above test, it seems clear here that D’s constitutionally-protected speech to the  radio station was not a “substantial factor” in his being terminated.
His speech was probably of “public concern,” given the “content, form, and context” and that it involved “a matter of political social, or other concern to the community.  Since it was a public forum, Pickering holds that the Pickering test will apply: The interests of the [government employee], as a citizen, in commenting upon matters of public concern balanced against the interest of the State, as an employer, in promoting the efficiency of the public
services it performs through its employees.  Here, the government’s
interest probably outweighs the employee’s.  Even though there is no
evidence in the case to suggest that leaking the letter interfered  with the efficiency of the school district, the Pickering Court suggested that using “inside info.” (i.e., a letter) could lead to a breach of efficiency that would allow the government to fire the employee.  Since there is no false speech, NY Times v. Sullivan would not apply.  Now, given that P’s speech is not protected under Pickering, it clearly cannot be a “substantial factor” in his being terminated under Mt. Healthy.  But assuming, arguendo, that his
speech is protected under Pickering, he still could not show that his
speech was a “substantial factor” in his being fired since plenty of
other episodes (i.e., his fighting with another teacher, his cursing
at students, etc.) justified his firing.