$15 an hour minimum wage (and re-unionization) -- all noble cause and political plums -- where is Obama?

I have been reading Richard Reeve's President Kennedy: Profile of Power this week. JFK had not much faith in the progress of the civil rights movement because he was afraid opposition attitudes were too deep and too long ingrained.

He did not seem to grasp that things never would change if somebody did not finally dig in hard and fight. I've read elsewhere that he said supporting civil rights would gain him 5% and lose him 10% of the vote. To his credit he voiced willingness to take on civil rights after his reelection.

In comparison to Kennedy's dog pile of disincentives to take on civil rights, what in the world is holding back Obama on the $15 an hour minimum wage (and re-unionizing America -- legally mandated, sector wide labor agreements the only way to go as far as I can see)?

The great majority of the public supports a raise in the minimum wage – even if the question is not presented to them in terms $15 an hour. Even if he could not sell $15 an hour (having said that, the arguments on the simple logical and eighth grade math level seem quite compelling), he would not burn up any political capital trying.

Some of the minority who pose minimum wage increases could actually be swung over to a lesser increase – no votes lost there. A minority of the great majority who might not want to go all the way to $15 would not by any stretch of the imagination become disenchanted Obama voters and switch to the Republicans.

All noble (desperate!) cause and all political plums; whoever peoples the planet that Obama is living on?