ArtemisI don't think campaigns can (legally anyway). Again, not a lawyer, just skimming some info, so do your own research or whatever, but it looks like—while exact details vary from state to state—generally speaking raffles have to be done by a 501c3 non-profit and may still have to be registered in some way with the state.
So if there isn't a "no purchase necessary" this seems like it's at least in some legally gray territory.
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