Washington (CNN) -- Superstorm Sandy's ability to wreak havoc on the most populated parts of the country this week has pointed out a noticeable gap in the 2012 presidential election -- how little the candidates have focused on climate change, the environment and other under-covered issues.
"With flooding in NYC and 3 feet of snow in W VA, isn't it time for candidates to address climate change and extreme weather," tweeted Darrell West, a director at the Brookings Institution, a public policy think tank.
Mike Tidwell of The Nation, a left-leaning magazine, was more direct. "The presidential candidates decided not to speak about climate change, but climate change has decided to speak to them."
The reason for this omission is simple: the 2012 presidential election has had a laser-like focus on a small handful of issues -- namely the economy. Meanwhile, other issues -- immigration, gun control, the environment and climate change -- have simply failed to break through among the candidates and in the media.
The last time both candidates mentioned climate change in any substantive manner was in written statements to a science organization in September. In interviews posted on Sciencedebate.org, President Barack Obama called climate change "one of the biggest issues of this generation" and Republican challenger Mitt Romney said, "my best assessment of the data is that the world is getting warmer" and "that many human activity contributes to that warming."
In what has been a breathless campaign, though, it is fair to say that throughout most of the campaign, both Obama and Romney have remained fairly mum about how they would deal with climate change. Both candidates have mentioned renewable energy, but the issue of a warming planet has remained on the back burner.
But climate change is far from the only issue that has received little to no attention. The eurozone crisis and its affect on the United States, the continued collapse of Mexico and -- following the deadly attack at a movie theater in Aurora, Colorado, this summer -- gun control laws in the United States have all received little to no attention.
Courting a certain demographic The primary reason a candidate includes an issue in his stump speech largely hinges on the kind of voter the candidate is trying to reach, according to Paul Begala, a CNN contributor and former aide to President Bill Clinton.
"Politicians want to get votes. To do that you have to: a) talk about issues that matter to voters, and b) talk about issues you disagree with your opponent on," Begala said. "Obviously a lot of important issues get left out."
And when those issues get left out, their importance seems secondary because no one is talking about them.
"Those (other) issues really are ancillary to what's on the mind of the American people right now," said Erick Erickson, editor-in-chief of the conservative RedState.com and a CNN contributor. "The American people are much more concerned with the economy and jobs. Were the candidates to focus on these other issues, they'd be accused of ignoring the big issue."
A Pew Research Center poll from October showed why the campaigns remain focused on the economy. When asked how important the candidate's position on unemployment would be, 91% of men and 89% of women said it would be extremely or very important.
Another Pew survey, however, showed global warming and immigration were at the bottom of a list of more than 20 issues. And polls from NBC News and NPR did not even list those issues among the top 10. The deficit, terrorism and foreign policy all rated higher.
Drawing comparisons But there are other reasons why those issues are often ignored. Campaigns like to draw comparisons with their competition -- division lines that make it easy for the voters to differentiate between the two candidates on Election Day. That is why, according to Erickson, Obama and Romney have remained mum on certain issues.
Why, he says, would Romney talk about abortion when he already has the pro-life community locked down? Likewise, why would Obama talk about gay marriage when an "overwhelming majority of people who are for the issue are already with the president."
"For the GOP, the election has centered on the economy, which has been the big issue Romney has had to litigate, so to speak, to persuade independents," Erickson said. "At the same time, the president has focused on women's reproductive rights to try to keep women in his camp. Both sides have focused on the issues they felt they needed to and sometimes the other issues necessarily get crowded out."
And activists and leaders in those issues groups have felt that crowding out. David Yarnold, CEO of the National Audubon Society, says he is "upset" that other issues have been ignored.
"I think the extremes on both sides have made that conversation almost impossible and in an election where the economy is front and center, it is hard for any other issue to break through," said Yarnold. "It is really unfortunate. It is yet another example where Americans are out ahead of their leaders."
But the lack of a climate change conversation has also compelled action from the Audubon Society. The group has partnered with ConservAmerica, a conservative conservation group, to try and take the politics out of conservation and climate change.
"We want to take the issue back," said Yarnold. "It is not left, it is not right, it is not center."
If most stump speeches are attempts to court votes, the best way to reach a lot of voters is through media coverage. The media has the ability to validate candidates by talking about the issues the campaigns are pushing, while holding candidates accountable to issues they don't want to address.
"The media has a crucial role in trying to get the candidates to talk about important issues they might otherwise want to dodge," Begala said. But the media can only do so much.
"Neither Obama nor Romney has any plans for new gun control laws," Begala said. "So no matter how hard the media or interest groups try, gun control just isn't going to be a big issue in the campaign."
This is normal Though the issues vary year-to-year, most presidential elections center on a few big issues.
When then-Arkansas Gov. Bill Clinton faced off with President George H.W. Bush in 1992, the main issue of the race was the economy. Bush had alienated much of his conservative base by promising to not raise taxes and then doing exactly that. Clinton ran on the idea that he could pull the economy out of a recession.
Moreover, after the dissolution of the Soviet Union, Bush's strong suit -- foreign policy -- was seen as an ancillary issue.
"In the history of elections in this country at the national level, it is very normal for there to just be a few issues discusses," Erickson said. "When there are no crises or major issues on the world stage, the economy becomes the big issue. How candidates talk about other issues depends on how they can tie those issues into the big thematic, overarching issue of the campaign."