A relatively smaller amount of money will influence state elections, and state-level politicians determine things like district boundaries (i.e. gerrymandering), vote roll purges, polling stations, etc. All of those have a very large impact on elections too.
1. More people voted for Clinton than Trump in 2016. If you look at the notion "More campaign funding = more votes", then this instance does not prove that wrong. It says a lot about Clinton's campaign strategy and America's election system, however, that she still lost the election despite more votes.
2. Trump still raised about a billion dollars. That is an insanely large amount of money.
1. The Citizens United ruling allows unbounded money to flow into campaigns.
2. Campaign funding determines election results.
3. Elected officials determine what America does in terms of law and regulation.
4. Billionaires pour tons of money into campaigns.
When you allow dollars to effectively determine elections instead of votes, the end result is oligarchy and the rule of the rich.