Democratic elections present a uniquely difficult set of problems to be solved by a security protocol. In particular, the ballot box or voting machine contains votes that may throw the government out of office. Therefore, it's not just the government--that is, election officials--that need evidence that no tampering has occurred, it's the public and the candidates.[...] In the late 19th century, after widespread, pervasive, and long-lasting fraud by election officials, democracies such as Australia and the United States implemented election protocols in an attempt to solve this problem. The struggle to achieve fair elections lasted for decades and was hard-fought.
It's a good point. I believe with modern mathematical tools, we should be able to develop good protocols much faster than a period of decades. However, before such problems can be solved, there must be an awareness that there is a problem at all. For whatever reason, elections all over the U.S. are using terrible voting machines and protocols that are worse than the old hole-punch machines. It's as if all these locales simply bought the voting machines with the lowest bid.
In general, government requisitions need to come with a long string of requirements, because officials are largely going to have to choose the cheapest product that meets the requirements. Anything not in the requirements is likely to be cut in the interest of cost savings. In the case of voting software, a key part of those requirements is to have sensible voting protocols.