Matthew Yglesias actually has off the record conversations with Democratic strategists and politicians. So i am sure this is not coming from nowhere. But when he writes an article saying that Elizabeth Warren has found a way to thread the needle between talking about income distribution and mobility/opportunity, i mean, i really have to scratch my head. I barely understand the distinction. This has been what's paralyzing Democrats from talking about this stuff? Do they really think the average non-engaged voter is having some nuanced internal debate, like... i mean i can't even articulate it.

Republicans, meanwhile, have their base worried that Obama is going to take over Texas. That's the difference in strategy between the two sides.

What Yglesias means is this: Democrats want to talk about how more and more wealth is being concentrated in the hands of the very wealthy. But the general public doesn't care about that. What they care about is that it's becoming more and more difficult for the children of the poor to lift themselves out of poverty into the middle class.
What I don't get is this- why do the Democrats want to talk about increasing concentration of wealth in the hands of the rich so badly? It's totally understandable that the public is primarily concerned with the inability of poor children to get out of poverty. And the "it was easier in 1945-1970 for a poor person to get out of poverty" argument favors the Democrats.