But it's not just Twitter. It's political media in general, of which journo-Twitter is only a particularly virulent subvirus. Stories that obsess Washington for days often fail to leave even the slightest dent in the electorate. And that's a bit of a problem because the reason the political press typically gives for swarming some gaffe or conflict is that it's going to matter in the election. We need that justification. Otherwise, what are we all doing writing article after article about some poor schmo who just phrased a banal point poorly? If it's just a misstatement, it's not a news story. But if it'll move votes, then it is a news story.
In theory, this kind of coverage can become a self-fulfilling prophecy: We say it will move voters, and then we give it a bunch of coverage, and so it moves voters. But actually, that doesn't really happen. Even when we try to get the public to care about some gaffe or conflict, they mostly ignore us. Remember "I like being able to fire people"? Or "Etch a Sketch"? Or "You didn't build that"? None of them moved the polls.
Sharknado is particularly clear example of our short reach. After all, for the public to clearly respond to our coverage of gaffes, they typically have to change opinions they already hold -- some Obama voters need to flip to Romney, or vice versa. That's a high bar to clear. But in this, all they needed to do was turn on SyFy and watch something fun. And they didn't even do that!
As I've written before, the first rule of being a political junkie is to always remember that you are a very weird person, and most people are not like you.
Related, kinda: 28 possible sequels to Sharknado.