

That is almost entirely a myth. Yes, there are ‘cross over votes’ in states that don’t have open primaries but facilitate party enrollment, but those cross over voters are almost always ‘independent’ voters who enroll and then unenroll and are not doing anything other than voting for the candidate of their choice in the primary that candidate is running in. So called ‘strategic voting’, as far as I know, has never made any difference in any presidential primary, but go ahead and bring up the bodies.
He spent 40B mostly of other people’s money. His liability is like 12B. The more interesting question is why various stodgy bankers gave him the other 28B.