Since the '80s, the left has howled in anger and laughter at "trickle down economics" -- the idea that "a rising tide lifts all boats". They have worked hard statistically and rhetorically to claim the the rich have gotten richer, but the poor are no better off. Much like thinking of global warming while the snow piles up in MN on the 23rd of October, they have managed to do this while the "poor" have cell phones, flat panel tvs, high speed internet and their most prevalent health problem is obesity.
Shrinking the "wealth gap" by making everyone worse off is a cynical way to "champion the middle class".
To some, Paul Krugman is a champion of the middle and lower classes given his desire to shrink the gap between those with and without money. But for his views on the dollar alone, it's apparent that his reputation lacks merit.
Krugman's support of weak currency policies erode the earnings of those who can afford it least, reduce the investment necessary to create jobs and wages, and drive down the very investment returns necessary to lift the fortunes of those seeking to increase their wealth. Far from a champion of the middle and lower classes, Krugman's views correlate with wealth destruction, and if implemented, his ideas will only shrink the wealth gap insofar as all of us will become worse off.