Has the lack of crypto ever stopped this from happening? Look up cases of gold bars being found in senators houses, those are actually MUCH less tracable.

Shitcoins and Shitstocks(some SPACs) do allow of a legal way to "give" others money through the transfer of value in a way that is technically legal. This again is not crypto specific though.

For me it was buying a computer from newegg but I confess I'm not playing in the same league.

There are a dozen better ways than Crypto to bribe politicians.