This is maybe the worst article I've read on the internet in a month. The article's argument goes something like this: the supreme court overturned some recent limits on campaign spending, and American campaigns might get more expensive as a result. The Roman Republic also had expensive campaigns during the first century BC. Therefor, campaign spending might destroy our republic, as it did Rome.
Lots of problems with that, but the biggest is that campaign spending had very little to do with the fall of the Roman Republic. The decades before the empire are largely a story of private armies fighting civil wars: First Marius raised a private army loyal to himself and dominated politics, than Sulla did, then Caesar and Pompey did, then they fought with their private armies and Caesar won, then Marc Antony and Augustus took Caesar's private army and killed the people who killed him, then they fought each other. Finis rei publicae. And those were just the big names, plenty of other people tried this "raise an army and take over" shtick. For example, the article mentions Cicero as a dude who hypocritically fought for less campaign spending. Which I guess he did? But his most important act as Consul was to put down the Catalinarian conspiracy, a plot to -- you guessed it -- raise a private army and take over Rome.
The Republic fell for a lot of reasons, and I don't want to oversimplify this. Roman politics at that time was an eddy of factionalism, ambition, and ideology as aristocrats fought demagogues (the optimates vs the populares) provincials fought citizens (the social wars), and patronage networks fought for dominance (see Cicero's entire legal career). But at the end of the day the Republic fell because individuals kept raising armies, starting civil wars, and seizing power. It's just not a story about messy political campaigns --Caesar and the senate didn't fall out over a super PAC-- it's a story about powerful generals with access to loyal veterans and large fortunes jockeying for power. Unless you have a much lower opinion of our officer corps than the average American, that is not going to be a problem here any time soon.