1. Political parties are brands. Just like buying a widget from Apple is done based on certain expectations based on the history of previous widgets, a political party instantly tells most voters what that person is for or against.
This is incredibly convenient to the vast majority of voters; and
2. The current state of politics in the US I think reflect's Hotelling's Law [1]. The parties have converged on the middle so they each get roughly half the vote. With such close elections and narrow balances of power in the House and Senate things are going to stay ugly.
Look no further than the current distribution of seats in the Australian House of Representatives [2] where the Gillard government clings to power with the support of 3 independents and 1 Green (76-74), a change of a single seat could change the government.
This has inevitably led to some bitter disputes [3] [4] that would be non-issues or much smaller issues if the government had a large working majority.
The problem with the US is not the electoral college or that only swing states matter (which largely misses the point). Popular vote deciding the president would be a fundamental change to the system that would (IMHO) ultimately lead to disaster when a close enough election repeated the turmoil of the 2000 Florida recount across the entire country.
The problem is that:
1. Voting isn't mandatory and the population is apathetic;
2. Voting is too hard being on a weekday and involving long waiting times. I would also argue that the long waiting times are symptomatic of (1). Partisan election officials have a vested interest in deterring or encouraging the vote in certain areas;
3. The FPTP (first past the post) system reinforces the two-party system whereas preferential voting systems allow "protest votes" without them being wasted or, worse, an effective vote for the other side;
4. Here's the big one: people are too predictable in how they vote. Of those that vote, 40% vote Democrat, 40% vote Republican and 20% decide the election. The Biggest electoral landslides in history (Reagan in 84 and Nixon in 72) have both garnered less than 60% of the popular vote.
This problem is so bad that in the redistricting process [5] there are maps produced of political persuasions that are used by the incumbent state government to redraw boundaries to maximize "their" Congressional delegation. This process is incredibly accurate because people are so predictable.
IMHO the choices in this election are pretty terrible. Romney, with his 47% and his "binders full of women" is a joke. Obama is the most IP-friendly and consumer and tech hostile president in history, from championing in secret a treaty (the original ACTA) that would've raised file-sharing to the level of terrorism and turned the FBI into the RIAA and MPAA's enforcement arm to filling the DoJ and judiciary with RIAA lawyers to his stance on software patents.
My advice? Given bad choices, which seem to abound, vote against the incumbent. The one thing politicians seem to fear is losing office with all the power and perks that come with it.
If this means you vote for a party you otherwise wouldn't, consider this: it's also important that your party doesn't take your vote for granted.
[1]: http://en.wikipedia.org/wiki/Hotellings_law
[2]: http://en.wikipedia.org/wiki/House_of_Representatives_(Austr...
[3]: http://www.boston.com/news/world/asia/2012/10/09/australian-...
[4]: http://www.bloomberg.com/news/2012-10-23/australian-lawmaker...