Can a city impose a permit fee on citizens for posting political yard signs?
No. Sometimes government officials can require payment of a small fee for the exercise of First Amendment rights, such as for a permit for a large group to march in a public park or gather in the public streets for a parade. However, the case is much different for a yard sign, because there are no city expenses to defray or offset. Furthermore, the U.S. Supreme Court has been vigilant in prohibiting taxes based on the content of speech. In City of Ladue v. Gilleo, the U.S. Supreme Court specifically pointed out that yard or window signs are “an unusually cheap or convenient form of communication” and that “especially for persons of modest means … a yard or window sign may have no practical substitute.”
Can a city prohibit political signs but allow commercial signs, such as 'for sale' signs?
No, the First Amendment, if anything, provides greater protection for political speech than commercial speech. Political speech is said to represent the core values that the First Amendment was designed to protect. The Supreme Court has created what has come to be known as the commercial-speech doctrine, saying that commercial speech represents a subordinate place in First Amendment jurisprudence. For example, content-based restrictions on political speech are subject to the highest form of judicial review, called strict scrutiny. On the other hand, content-based restrictions on commercial speech are subject to a lesser form of review, called intermediate scrutiny. What this legalese means, in essence, is that yard signs on political topics are entitled to at least as much (and probably more) protection as commercial signs.
Can neighborhood, homeowners’ and condo associations restrict residents in displaying signs, flags, decorations, etc., outside their dwellings?
Yes. Such associations are private entities not covered by the First Amendment. Sometimes the contracts residents sign in order to live in the condo or neighborhood specify restrictions or prohibitions on such displays.