It'll take a lot more than a bad president to doom America. Here are the things that stand a shot at dooming America:
Media is treating the presidential race like a circus - just having half an ear to what is being spouted out on the TV and other major news sites, all you can tell about the presidential nominees is that one is a "hip" black muslim who wants to "change" something unspecific, and the other side is an old white guy with a female Vice Pres. Now no matter which side we vote for, we get to be groundbreaking purely for the sake of being groundbreaking. Isn't it great?
World Opinion = presidential qualifier? - Excuse me, but why the hell should any presidential candidate be touring the world during their campaign at all, not to mention before they've even secured the nomination for their own party? I don't recall any citizens of Europe Asia and Africa having any voting rights. I don't really remember hearing England ask the US if we were okay with their queen before she was coronated either. Sorry, but what the rest of the world thinks comes AFTER what the citizens think. No nominee
Victimized society and loss of responsibility - Lawyers and politics and every single policy you see anymore is entirely geared towards trying to push as much responsibility as possible onto someone else. People sue because of their own stupidity that they aren't willing to take responsibility for, and other people are forced to create policies that strip away as many of our rights as possible in order to protect themselves from being the ones stuck with that responsibility.
Minority mindset is a subgroup to this in which people find whatever they can in order to separate themselves from the majority since the only way people can have a voice is no longer through a majority, but through adding their voice to whatever specialized group has managed to garner attention as being ignored or "victimized." Instead of the majority opinion being represented, only the smaller needs are addressed, often at the expense of the majority, which in itself includes several other minorities. Since these minorities are at a disadvantage they will clamor louder for their own needs to be addressed and the cycle will continue.
Unions, minimum wage, and endless inflation - a person earns money through how much work they do. In order to make a profit on an item that is being sold, the price must cover the costs that went into making it. Minimum wage is determined by the minimum a person must make in order to be able to survive, which in turn depends on the price of basic necessities. If minimum wage goes up, then so will the cost of basic necessities which will then require a raise in what is needed to survive.
One of the largest problems that stems from this is that when minimum wage goes up, only the people at the lowest pay scale benefit from this. If someone had been working for minimum wage and got a raise to $7, and then minimum wage was raised to $7, they would now be back to working for minimum wage. Ultimately, the minimum wage is pointless; if people only worked for $.05 an hour, then companies wouldn't have to charge as much for their products in order to make a profit. This issue is further compounded by how many union contracts are written, which often have payscales for senior members(skill isn't an issue here, only seniority) set to be a multiple of minimum wage. If minimum wage increases by $.05, their pay may raise by $.25.
All this stuff, and a few other things on top of it are what I see dooming America. We care too much what other people think of us and we're too willing to push our responsibilities off to someone else.