As AP notes, the option to choose "none" was designed as a countermeasure against apathy following the Watergate scandal that brought down Richard Nixon. Earlier this year, Republicans financed a lawsuit to get rid the choice.
Why? Largely because of the incumbent at the top of the ticket, about whom most voters have formed an opinion.
The idea is that voters unimpressed with President Obama's four-year record but not impressed enough by Mitt Romney might go with the option of neither. If voters don't have that option, they might be tempted to go with the alternative to the status quo, which is Romney. Similarly, voters lukewarm about Romney who are not considering voting for Obama could opt for neither. But the absence of the "none" could notch the Republican a few more anti-Obama voters.
"Few" is the key word here. A review of recent presidential election tallies reveals that a very small slice of the Nevada electorate has tended to prefer the "none" option.
In 2008, less than one in a hundred voters (0.65 percent of the electorate) decided to cast a ballot for "none of these candidates." In 2004, less than half of one percent (0.44 percent) chose the option.
"It hasn't gotten more than 2 percent in any presidential race since 1976," noted Nevada political analyst Jon Ralston.
In other words, the 2012 race would have to be awfully tight for "none" (or its absence) to be a deciding factor.
That's not to say such a thing can't happen, or hasn't happened. In 1998, incumbent Democratic Sen. Harry Reid (D) defeated Republican John Ensign by just 400 votes, when over 8,000 voters cast ballots for "none."
More recently, the 2010 Senate election shows that even in a race with two flawed candidates, "none" did not attract all that many votes. A little over 2 percent of the electorate chose the option that year, in a race Reid won by about six points.
Recent polling on the Silver State Senate race shows a single digit contest between Sen. Dean Heller (R) and Rep. Shelley Berkley (D). So a couple of percentage points could matter if the race remains tight. And in the context of the broader race for an upper chamber majority, the stakes are even higher.
The presidential race also looks very competitive. Still, it's worth bearing in mind that "none" hasn't cracked the 1 percent threshold in the last three presidential elections.
Nevada's Democratic secretary of state has vowed an appeal of the ruling striking down the "none" choice. The legal battle appears to be unfinished, but its ultimate outcome may not dramatically impact the marquee statewide elections.