The initial difficulty with implementing an online voting system in any country is the number of individuals who would be disenfranchised as a result of the new methods. In the United States, where a national online voting platform could be created, at least 77% of residents are Internet users. At first glance, this does not seem like a hindrance to participation when traditional polling is also put in place. This would leave American voters with the option of utilizing an online voting system or showing up to their local polling place.
As the Estonians have been doing for the past 7 years, phasing online voting in while maintaining physical polling places allows voters to opt-in to online ballots. This creates a scenario where voters who have Internet access and will participate online do not have to hassle with showing up at a physical polling place. For many voters one day and one location can create a logistical situation that keeps them from participating.
If the United States were to implement an online voting system it should be phased in over several years. A drastic transition to online elections would likely leave voters confused and leave many without an opportunity to participate. As the Estonians have done successfully, an online option should be presented to all voters, but it should not be the only option.
Although the New South Wales election was extraordinarily successful, the Australians have a compulsory voting law in place. What could be overlooked is the number of people who were enabled to participate in the election that had physical barriers to voting prior to online elections. Making online ballots accessible to voters who live far from polling places or who have physical disabilities can only encourage participation.
Leaving the voting window open for several days presents the opportunity to vote at your convenience or change your vote following later research or statements from candidates. Although this could create a larger security risk, it would allow for more voters to cast a ballot.