Among the most valuable assets in any nation are the knowledge, skills and productive experience that economists call "human capital." When successful people with much human capital leave the country, either voluntarily or because of hostile governments or hostile mobs whipped up by demagogues exploiting envy, lasting damage can be done to the economy they leave behind.
Fidel Castro's confiscatory policies drove successful Cubans to flee to Florida, often leaving much of their physical wealth behind. But poverty-stricken refugees rose to prosperity again in Florida, while the wealth they left behind in Cuba did not prevent the people there from being poverty stricken under Castro. The lasting wealth the refugees took with them was their human capital.
We have all heard the old saying that giving a man a fish feeds him only for a day, while teaching him to fish feeds him for a lifetime. Redistributionists give him a fish and leave him dependent on the government for more fish in the future.
If the redistributionists were serious, what they would want to distribute is the ability to fish, or to be productive in other ways. Knowledge is one of the few things that can be distributed to people without reducing the amount held by others.
That would better serve the interests of the poor, but it would not serve the interests of politicians who want to exercise power, and to get the votes of people who are dependent on them.
Barack Obama can endlessly proclaim his slogan of "Forward," but what he is proposing is going backwards to policies that have failed repeatedly in countries around the world.
Yet, to many people who cannot be bothered to stop and think, redistribution sounds good.