Regarding money in politics (the effect) and its cause:
The real cause is the growing regulatory state. Without regulation,
there would be only limited incentive for corporations and individuals
to make large political contributions. Regulation (combined with
taxation) is the fountain from which most campaign money springs.
Threaten to regulate a sector, and you automatically put politicians in
the position of creating winners and losers, both of whom will spend
money to try to improve their fates.
Say it ten times, so you don’t forget: "money is the effect; the cause is government force." Again.