Yeah, they care about power. But if Obama hates America, as you claimed in the original post (and topic title), why would he try for the Presidential job? Or stay in America? There are better ways to acquire power in this country without becoming part of the government, an integral part of the country he apparently hates.
Let me ask you a question.
Let's say you meet a woman and you fall in love. Let's say you pursue her hand in marriage, do you go about it by telling her you love her, but you want to fundamentally change her? Not if you wanna keep your penis you don't.
The only way I could see her fundamentally changing her and still actually loving her was if she had some habit that was destroyed her life. Drug addiction, chain-smoking, alcoholism, kleptomania, etc.
But she could have other problems to work out as well. She could have anger management issues, or be far too naive and trusting of complete strangers, or be a complete and total flake, or have massive self-confidence issues. So you help her through those problems in order for her to become a better person. Even though you could very well argue that be helping her through those issues your fundamentally changing her.
But your analogy of Obama as the chap in love and the United States as the woman he wants to change doesn't work. Following it means we must also assume every politician, Congressperson or President hates the country for changing in some way because nearly all of them since the founding have upset the status quo in some way. In many places fundamentally changing it. Like the addition of new states, or all the amendments we added to the Constitution.