Suppose a section 1983 plaintiff alleges that a city had him arrested in retaliation for the exercise of his First Amendment rights. He claims that he was arrested (although never prosecuted) at a city council meeting when he got up to speak because he previously had criticized the city’s eminent domain redevelopment efforts and had also sued the city for violating the state’s Sunshine Act.
Ordinarily, such a plaintiff, in order to make out a section 1983 First Amendment retaliatory arrest claim, would only have to allege and prove that this impermissible retaliatory motive caused him harm, and the defendant would have the burden of disproving the absence of but-for causation in order to escape liability. But here the city argued that even if its motive was impermissible under the First Amendment, there was probable cause–an objective Fourth Amendment standard–to arrest the plaintiff anyway, and that this constituted a defense to the plaintiff’s First Amendment retaliation claim. What result? (more…)