This is going to be my impression of events, past and current. I may have things wrong. The source of the problem was lawlessness, but the problem was money. It's a problem that's still around, maybe worse today. Time to dig deeper.
Prohibition was essentially The War on Alcohol, and people did like drinking. The goal was to break the excessive drinking habit, but it went too far by banning almost everything except home-made wine. The Volstead Act included fines that would be punitive for individuals. However, Prohibition created a black market for alcohol and organized crime quickly filled the need. Supply and demand; if there's a demand, there's a market for the supplier.
Organized crime made mad bank supplying alcohol to thirsty patrons whose numbers included politicians from the municipal level to the federal. How much bank? Purchasing a politician was just a write off in the ledgers. And if politicians could be bought off, what about local police and agents from the Bureau of Prohibition? A $3000 bribe that could be a rounding error on the books for a speakeasy was easily twice the salary of a rookie cop or a newly appointed agent. Even for higher ups on the force, that $3000 is tempting, and someone else would take it if the law enforcement officer (LEO) didn't. Even buying a politician was a good investment, provided the pol remained bought. Prohibition agents originally were signed on on the recommendation of politicians instead of a proper hiring process. A bought pol could get a corruption-friendly agent in the Bureau. There was a a reason why Ness' team were called "The Untouchables" - the corruption rate of Prohibition agents was 90%. Agents were underpaid, overworked, and dealing with corruption from above. Why bother doing anything other than going through the motions?
Of course, the best way to correct the problem and take funding away from the mobs would've been to just end Prohibition and chalk it up as a failed experiment. In Canada, that was easily done. In the US, however, the Temperance movement had Prohibition installed through a Constitutional amendment, the 18th, avoiding the need to get bills passed by both State and Federal Congresses. Repealing required two-thirds of all states to ratify the 21st Amendment. In the wake of Prohibition, organized crime had gained a foothold and made obscene amounts of money. That money was used to corrupt police and politicians, creating distrust among voters.
Fast forward almost a hundred years to today. Citizens United allowed corporation and other moneyed interests unlimited spending in elections, equating money with speech. Problem is, money corrupts the process. Politicians stop listening to the electorate and to the people supplying money to election funds. This time, though, it's from legit entities. Instead of being bought off by organized crime, politicians, particularly Republicans right now, are ignoring voters' needs to grant their corporate and welathy donors their every desire, like massive tax cuts.
The parallels are there. Laws are getting rewritten to benefit a chosen few. In the 1920s and 30s, organized crime got to benefit. Now, corporations and the extremely wealthy. France had a solution for that with specialized hardware. There is a solution the can avoid violence, and this time it doesn't require a Constitutional amendment in the US. Get the money out of the electoral system. Money corrupts the process. The problem with this solution is that the people involved benefit from the current system.
This year, though, is showing that the people are tired of empty words from the people who are supposed to be running the show. The US is on the brink and desperately needs Constitution 2.0 or a large number of service packs to fix things. The first thing to be fixed is getting money out of the electoral process and the running of the country. Stop electing businessmen; government is not a business and cannot be run as one. Start looking at history and see when the greatest unrest came about and the causes. Remember the lessons of Prohibition and of why it was a failure.