They're letting it happen because they're going to seize it.

I bought a black MAGA hat. My contribution to the 400 million is: 0.00001175% 47 / 400000000 x 100% = 0.00001175%

An interesting theory I read is that the elites will use the The National Popular Vote Interstate Compact (x.com) to make some states go against their own voters and give their electoral college votes to the national popular vote winner. If they can remove Trump from the ballot in a couple of blue states Biden will win the popular vote and any Trump supporting states in the compact will be forced to turn.

The compact does not yet have enough states to come into effect, so it’s only a possibility right now.

Waiting for the RNC to "decide" that they need a different candidate due to Trump's felony convictions... war mongering RINO enters stage right.

Trump is campaigning mostly against his own party apparatus. The dems are not campaigning at all as far as I can tell, which is probably a dark sign. Something is up, either the fix is in and they don't care that it will be even more blatantly obvious, or they are not planning on having an actual election. This could occur in a few ways, probably the most likely of which at the moment would involve some sort of large scale military escalation. They'll literally start WW3 to stop Trump from wining.