It is generally reported that the AFL-CIO was hedging bets towards taking further steps towards active political support in campaigns related to labor issues, while the four that broke ranks headed by the SEIU and Teamsters was looking to invigorate the unionizing process in America and rebuilding the base of union members. Without a compromise, the split took place. Nothing that I can find establishes the permanence of the break, but let us assume that it is going to stay broken.
If the AFL-CIO is right and that the only way to keep strength is through numbers and political donations, then the past ten years have been resounding defeats, yes? A loss of Congress, two consecutive lost Presidential races to a candidate not known to be particularly kind towards unions, and a shrinking membership base through lost manufacturing employment might make one scratch his or her head. Do campaign donations and get out the vote efforts improve the underlying structure?
If the Change To Win Coalition has it right, then placing higher goals on attracting new members and rebuiliding the organization's base might increase overall participation within the labor movement, and increase the vitality of an institution that has not seen the best of days lately. I don't see Big Labor being wed to the Democrats in D.C. as being the right cause to fight for at this moment. I do see AFL-CIO President John Sweney's comment, "...our future should not be dictated by the demands of any group or the ambitions of any individuals," as precisely what might be wrong within that organization. Listen intently to those who deeply care about the future lest you be left behind.
While reading sites about labor unions, I came across a decent history at the Department of Labor written by many historians. It might be good rainy day reading provided you live in monsoon territory.
And lastly, a quote from Lincoln:
"Labor is prior to, and independent of, capital. Capital is only the fruit of labor, and could never have existed if labor had not first existed. Labor is the superior of capital, and deserves much the higher consideration. Capital has its rights, which are as worthy of protection as any other rights."