Is the Internet destroying the U.S. two party system?

The big problem with modern politics (US or otherwise) is that the issues are bundled together without any regard of being connected other than "it was always bundled this way", like gun ownership with gay marriage with market regulation.

Society can't hold politicians accountable for specific issues, it's always a package. The (hypothetical) guy did a good job on banking regulation, but made sh&t all over intellectual property, and he only can be "fired" as a whole, by not being elected later.

And now try to rally up enough force because of the IP bill! You won't get much leverage, because you attack him, which includes banking issue, so you'll get an opposition that doesn't care about IP, but likes his work about banks.

Why not reward him for the former action and punish for the latter?

That cannot happen until the US does away with first-past-the-post voting.

A good first step would be to get rid of the R and D next to names on state sponsored ballots.