Romney is not doing that. He has written off 47% of the country as not worth campaigning for, and I can guarantee you that he knows he can't attract young people at all because of his stance on student loans and women's health care.
It doesn't matter, Obama will campaign to attract non-white and poor voters, it doesn't mean he will actually do anything to help them.
By saying that he is not the lesser of two evils, you are saying that Romney is a better choice.
It certainly does not. Saying X is not better than Y does not say Y is better than X.
Are you seriously suggesting that a racist, homophobic, sexist, privileged rich white dude who doesn't have any clear policies on anything (except, of course, fucking over the middle class) is a better choice than a right-of-center Democrat? Is that seriously what you are suggesting? Because I'm not seeing any evidence for that whatsoever.
Right of centre? This is what you describe someone who unashamedly supports the bankers, is more than happy to chum around with neo-liberals, attacks unions and workers (not that American unions are any good) and destroy social security? Just because Obama isn't as openly sexist and homophobic as Mitt Romney doesn't mean he has done anything good. Wow, he removed DADT.
A) The Democrats are losing support, which is also why he came out in support of same sex marriage rights though he hasn't done anything, and so they need to regain support.
B) The American military is facing a recruitment crisis
What's that about women's rights? A shit ton of states have passed laws attacking abortion and contraception rights? Especially in his first two years, where Obama held a majority in both the House of Reps and the Senate? But then, defer for the first two years and then blame everything on the Republicans. Easy.
I'm not seeing how Obama is any good. At all really.
Also, the idea of voting for the lesser evil is bullshit. Specifically for America, the Democrats are not a social democratic party, they are a liberal bourgeois party. There is a difference between the Democrats and the Labour/Labor/Social Democratic/Socialist parties of Europe and Australia. The latter, no matter how shitty and terrible they are, have some connection with the working class (though that is not to say that I would endorse them). Also, voting to keep the Republicans out allows the Democrats to move as far to the right as they want, they can simply point to the Republican menace to gain left-wing support, and then justify any rightward shift as a means to gain votes.