Bloomberg bankrolls a social-media army 6 years ago
Donald Trump spent on his campaign almost half the money of Clinton's campaign, and he won the presidency despite having raised less than any major party presidential nominee since 2008 [0]. So, if your concern is a candidate "buying" an election, Trump would be the worst recent example one could use.
[0] https://www.bloomberg.com/politics/graphics/2016-presidentia...