So yes, on an individual level, your vote is worthless. However, in the aggregate, constituent feedback counts for a lot, possibly the biggest single input. And so once you accept that you as an individual are insignificant in the grand scheme of themes, you can actually accomplish a lot by minimizing the personal effort you expend on writing your congressperson and instead getting lots of other people to vote the same way you do.
This suggests an interesting hack. Create a really simple mobile app that lets you subscribe to all upcoming legislation on issues you care about. It'd be structured like a news app or RSS reader, where you can flick it open whenever you have a spare moment and read the latest upcoming issues. And then let you easily indicate your position - perhaps swiping right means "Aye" and swiping left means "Nay". A swipe automatically sends a canned form letter to your congressman indicating your support or opposition for the legislation.
Basically, you're leveraging technology to enable direct democracy. Create a direct information line between constituent and congressperson, where the constituents have all the information available to them that congresspeople do, and can vote just as easily.
I recall the creator talking about this at length on reddit or somesuch in recent months.
Also Direct Democracy is a nightmare. See: California. Arnold Schwarzenegger outlines why his attempt at making most of his major issues ballot initiatives in his first term was a disaster in his book Total Recall.
[citation needed]
I highly doubt this is what was said, because it's simply not true. I certainly don't remember it being said either. Certainly, if that was the the "overwhelming response", you should have no trouble providing links. If you do, i'm happy to admit I was wrong. As far I know, having talked directly to legislative assistants of congressman, and chiefs of staff of senators, is that they are a huge input into how congressmen and senators vote.
Excerpt from first reply:
"ETA: I've also typically seen that regardless of the amount of pressure applied by the public for one side of an issue, nearly every politician will simply vote the party line anyways. They know where their bread is buttered, and won't go against party leadership. I've watched legislators look over at a senior party member and be signalled which way to vote when their turn comes up. I don't think anything I've done or said to my representatives has had the slightest impact on their opinion or voting record. That's just how the game is played."
Excerpt from second reply:
"IME: email is worthless. canned letters / faxes go in the garbage. A polite phone call may accomplish something. Better yet if you donated or voted for that politician. Even better if you phone banked." [followed by an explanation of what works, i.e. money]
Excerpt from third comment:
"I was an intern for a congressman. My job was to answer and return constituent emails and calls. We took the feedback, searched for the proper prewritten form letter, printed it out and sent it back with a stamp of the congressman's signature. He never got a single bit of the feedback himself."
Fourth comment mentions that anti-SOPA call-ins seemed to have been successful, but they are forgetting the billions of dollars of corporate money that went into protesting SOPA. Again, it was about money.
So basically, anecdotal evidence. Got it.
This issue has been discussed on HN before, and we had overwhelming response from people who actually worked for Congresspeople that the vast majority of letters and calls from constituents get either ignored, or given canned responses. This fits my anecdotal experiences with politicians in general as well - for the most part, the politician is paid for by private interests and lobby groups.