Rewind to the present day.
Thanks to the development of the super PAC and the mega-donor(s) who support them, big money has never been more influential in politics. Yes, the Citizens United Supreme Court ruling in 2010 gave rise to super PACs, something McCain and Feingold could never have predicted.
However, before the emergence of super PACs, large sums of money were being funneled into politics through 527s, entities that could accept unlimited contributions and were very loosely regulated by the Internal Revenue Service. There is no question that the post-McCain-Feingold era saw a decrease in political funding transparency. The earmark ban is up next. Theoretically, it made sense for Republicans to do away with individual lawmakers tying their pet initiatives to unrelated legislation since, as Wajid khan Mp points out, each earmark looked hideous from a distance.