All in all I think the preference system and mandatory voting makes for a far healthier democracy.
Me voting for a third-party candidate is does not imply that I would have voted for any other candidate had they not been on the ballot. Had that candidate not been on the ballot, I would have abstained from that particular position.
It's like the BSA argument that people who steal software (yes it's stealing) would have normally bought the software. No, they wouldn't have.
Really? If there were three candidates, one who was 95% in agreement with you, one who was 85%, and one who was 30%, and the 95% dropped out of the race, you would just NOT vote for the 85%?
But I refuse to vote for a candidate because of a single plank or even 2 or 3 planks. I won't compromise on things like marriage equality or abortion rights. Those, while they should have no federal interferance at all, sadly are determined at the federal level. Same goes for economy.
But if the candidate has an opinion on, say, the Department of Education that I'm opposed to I might let it slide.
The point I was making is that is a case by case basis and more times than not, I've refused to vote for any candidate because I didn't want to send a message that I supported them at all.
If everyone informed chooses not to vote for anyone, all that does is give more power to the uninformed.
We effectively do have a "none of the above" option: don't select anyone and still cast the ballot. However, it would be better if there was an explicit "No vote" option.
The biggest problem with voting not being mandatory is that a lot of people don't have the opportunity because they can't get off work. If you made voting mandatory (or at least made election day a paid holiday), this impediment might be alleviated.
http://en.wikipedia.org/wiki/Election_Day_%28United_States%2...
http://usgovinfo.about.com/od/thepoliticalsystem/a/whenwevot...
I point this out to anyone who complains about how archaic some things in the UK or Europe appear to be.
However, in this country there is a constant struggle between trying to let more people vote versus trying to restrict voting. Hence why a lot of people are up in arms about potential voter fraud. The traditional wisdom is that more voters helps one party, fewer helps another. With this as a factor, you can see how it would be very difficult to change the day of voting to make it more convenient for people.
The date is set by an act of Congress from 1845.
http://memory.loc.gov/ll/llsl/005/0700/07590721.tif
I think my other arguments still stand though...
An alternative, as it's done in Spain, is to give everyone the right to leave their jobs in order to vote. To alleviate things for businesses, all elections happen on Sundays.
That just sounds like a lazy excuse to me. I don't know how long it takes to vote in the US, but where I live in Canada, we just finished our municiple elections. It was one of the longest ballots I can remember, yet the entire process, including walking from my house to the polling station and back, took about 20 minutes after work.
I have to say, I just don't understand this voter apathy or this sentiment that if none of the candidates are any good then don't vote. I really do think it is your duty as a citizen.
And don't forget Gerrymandering, in which the party in power redraws the voting district lines to ensure that every district has a majority of their party (though that happens before election day): http://en.wikipedia.org/wiki/Gerrymandering
Edit: I added a few more examples from other replies that represent common methods of intentional sabotage.
Broken electronic voting machines.
Higher than expected turn out resulting in a backlog.
Showing up after work along with a huge group of people doing the same thing.
And I suspect some state level manipulation because my area (Northern VA) does not vote for the same party as the rest of the state. Other polling stations with 1/5th the population have the same number of voting stations.2 of the 6 machines the precinct received did not verify when turned on. They're an electronic booth with paper printout (yes,what the vote hackers wanted to begin with). However the paper did not agree with the electronic tally, hence machine invalidated.
And they got 4x the turnout they were expecting. Now, usually, it's 20 min in line and 3 min for the vote itself.
In the US each elected official, whether they were a Democrat nominee, a Republican nominee, or a member of one of the other parties chooses who they will caucus with. That's why people like Arlen Specter can change parties freely.
And allocating seats based on the percentage of people who voted in each state ignores those who don't have the right to vote - whether they're children, foreigners, or people in other categories. Once someone is elected, they're supposed to serve their entire constituency, not just those who voted for them.
And finally, the US (and no country that I can think of, really) is not a democracy, it is a democratic republic. The many elect a few to govern, and those elected to govern are supposed to do what is right - and what is right is not always what the majority wants.
The only way to say 'none of the above' is by filing an informal vote. This is a de-facto way of saying that you don't like any of the options, and at least in Australia this informal vote is tracked and parties take notice of it.
In the USA if you vote to not vote, Washington bundles you in with everybody else and assumes that you have no interest.
The ideal solution would be
a) Voting is mandatory, but with a formal 'none of the above' option
b) Voting is not mandatory, but representation is allocated based on what portion of total people voted for you, not allocated based on the portion of the total vote. (ie. if in one state all 25M people voted, they should get 5 representatives in congress, while if in another state of 50M people only 5M votes, they should only get 1 seat in congress)
With a quota based system based on proportion of population congress/parliament would then be a true representation. It is the only way to reflect the will of the entire population, meaning that those who choose to stay at home can no longer be ignored.