You would have in the case of the US around 150 million tx, the mempool now holds 20,000, the max was 600 000.
Let's assume you somehow manage to run some nodes being able to hold all those you have another problem, which most bitcoin users would not want to deal with. Each address would have to be registered with an individual, it will tie that address to your identity forever, exposing it maybe, the second one is the problem of getting hacked, how would the authority decide which vote is the right one if your address sends two tx!
Now the funny thing, it would take a **** of space to fund 150 million unique addresses, bloating the blockchain for weeks.
It's a real crude, very time-consuming, and dangerous to the voting secret.
There are plenty of other solutions readily available, like i-voting, and it runs on top of a blockchain.