How thoughtlessly we ban core First Amendment activity: first to prevent corruption, then to corruptly silence dissenters
The case of Brinkman et al v. Budish et al illustrates how easy it is for lawmakers and reformers to go overboard, once they are given any leeway to restrict lobbying, political contributions, or political advocacy. The original reason for laws that did this -- restrictions on campaign contributions, and laws against "revolving doors" that let the legislators who govern an industry look forward to well-paying jobs as that industry's lobbyists -- was to fight what looked like bribery of politicians by big businesses. Even that, important as it is, should never have been an acceptable reason to allow any restriction on what the First Amendment was principally designed to protect.
But once we allowed those laws to be passed, essentially as an exception to the First Amendment, we seemed to quickly forget the reason for the narrow exception, and came to believe that lobbying, politicking, and contributing to political campaigns were inherently suspect activities that should always be regulated. And that all noncompliance is not just a regulatory offense, but morally criminal. Thus we've had laws against "bribing" officeholders with campaign contributions used against people contributing to ballot initiatives, or even just directly advocating for them, or for or against a candidate.
In Brinkman, a "revolving door" law was used against a former legislator who did unpaid lobbying, and did it for a group that advocated broad principles and issues -- less taxes and spending -- instead of for a business or an industry. And that's where a federal court drew the line and said that such laws had gone too far.