“....spent more than $155 million to rack up high primary-vote totals for a nomination he had no chance of losing.”
That is a highly speculative spin by the author. There are a number of other motivations for him spending that money and holding rallies other than to inflate his primary numbers.
The rallies rack up tremendous voter data for the campaign. They may only get 19,000 people in the stadium, but they have the contact info for 100,000 potential campaign volunteers.
For one, he gets to start his Presidential run against Biden early. Really he needs to emphasize law, order and the importance of our history.