It comes down to incrementality. Sure Trump has way more money than most challengers, but most people have also already made up their minds about him. His cost to acquire incremental voters is probably much higher than a lesser-known challenger.
I would expect that to require an extremely huge amount of money and be impractical.
Candidates + parties + PACs + lobbying + think tanks + advocacy organizations spent $10B in 2018 in the US, whereas the US almond industry made $12B in 2018. So I expect political spending to not be able to change ad prices very much compared to commercial ad spending.
Yeah I very much doubt Trump is wasting his money bidding on impressions for people likely to support Democrats (assuming he can accurately mimic the dems’ targeting) just to slightly raise the cost of Democratic campaigns
As someone who lived through Meg Whitmans's carpet bombing when trying to win the California governorship over Jerry Brown, it's hard to believe that would matter.
For me, it just made me annoyed at Whitman.
A quick googling gave this¹ doc, that says MW spent $178.5M against $36.7M from JB. Brown won easily.
