Because politicians can’t think of anything else to try and win.

I can answer that Twilight.  
FLAME SHIELD ACTIVATED  
They’re waqsting time on attack ads rather than who has better ideas is because neither side has any ideas. No matter who wins they do both uphold the same policies because they both work for the same corporate mechanism that basically rules the country. Democracy is an illusion and the politicians provide the smoke and mirrors.

I like this BP. Wish you had a name I could write down somewhere so I could remember to like you. Oh well.

In short, because neither of them have particularly good ideas and both are on the record with a disturbing array of human rights violations, so making the other guy look like the greater devil is easier than passing oneself off as a good choice.
 
This is exacerbated when most of the constituency consumes almost exclusively news media owned by a small number of people with a vested business interest in one candidate or the other. These voters get saturated with a heavy, aggressive bias that they’ll either see as enthusiastically reinforcing their current worldview or violently opposing it thus making them “the enemy”.

Mankind the one thing on this planet capable of destroying it faster than anything else in existence. Including meteors.

Because conflict is a large part of being human. It exists in every avenue of human culture. A few of us choose to not participate in the perpetual stimulation of this aspect of humanity but until the majority of our species decides that conflict is pointless then the struggle will continue. Its one of the many reasons I hate humanity.

I agree with boogstersu2.  
I’m voting for Obama.

Because people are evil as a matter of course, and that means it’s much easier to show what a terrible person your opponent is than what a good person you are. Because chances are, you’re a pretty terrible person.

@boogstersu2
 
True facts.

We’re only human.

Only Stewart and Colbert gives us positive facts on politics!

Nice moniker, Vitruvius.

Ha, Clint Eastwood and the chair.

It’s a prisoner’s dilemma, but no one can afford to be nice.

Bread and circuses; that’s all it’s ever been.

Americans are easily distracted and tend to focus on the negatives more than the positives. I should know. I live here.

I don’t see why people feel the need to put their own words into the mouths of ponies.

It’d also be cool if most of the attacks were actually based on fact

Because masterbating with tambourines

To make people fight amongst themselves so they accomplish nothing. If everyone is fighting with each other over which party is better and non-issues, the parties can work together and get more power.
 
>Wouldn’t it be better if you focus on which candidate has the better ideas?
 
How? they both have the same ideas.

the point of american politics is to make the other guy look worse.

Because reasons.

better? yes  
more entertaining? maybe  
That’s american politics Twilight it’s not about making your ideas seem good it’s about making the other person seem bad  
but honestly not very involved in the political process myself

Negative attacks are proven to be more effective and galvanize the bases more efficiently.
 
It’s also easier to attack your opponent if you don’t have much to stand on yourself.