Barack Obama knows that increasing any taxes, even for the rich, will further damage this weak economy. That's why, in 2010, when the economy was stronger than it is today, and, when he had complete control of Congress, he chose to extend "all" the Bush tax cuts for two more years. He could have easily done what he is now suggesting; which is to extend them for everyone "except" those making more than $200,000, individually, and any families making more than $250,000. But, this is an election year; and, Obama is trying to set up a straw man argument in order to bait the Republicans into defending an extension of the Bush tax cuts for the rich.
Politically, I'm sure that he thinks he can achieve an electoral advantage by aligning the Republicans with the one percent who are rich and by having himself emerge as the protectorate of the 99% who are not. Simply, it's a continuation of his class warfare politics. It also takes the focus off his miserable stewardship of the economy and our high unemployment. Also, think about this. Would raising taxes on the rich grow the economy or reduce unemployment? Of course not. In fact, it would do the opposite. That's why Obama's whole argument is more about him getting reelected and not about helping this country.