In theory, since the block is stored on multiple nodes (computers) then it would be hard for one node to disappear and the data being lost. Or, it would also be hard for someone to change the data after the vote, if is already stored in the blockchain.
Being able to check the valid data is the issue with computer voting.
Of course, the vote tallying machines can also be hacked and take a paper ballet and record a different vote. So, as long as the paper ballot isn't destroyed immediately after the election, you have that safe guard. But, only if someone suspects wrong doing.