In what way? The cited portion, which discusses theories in the field, says:
“The rainbow theorists argue that the machine was a functional body (Merton 1968) that pursued political incorporation of many ethnic groups in the political party. In return for loyalty to the political party, machines delivered a variety of social services to ethnic immigrants, in addition to jobs, friendship, and opportunities for social and economic advancement. The rainbow coalition of mostly white-ethnic groups was sustained through a virtually endless supply of ‘municipal gold’ (Erie 1988) that the machines controlled. This exchange system seemingly guaranteed ethnic loyalty to the machine.”
The remainder of the article shows how Irish domination left the Polish with the short end of the stick: “Through this study we try to show that Polish Americans in Chicago were on the short end of the exchange arrangements in the machine, receiving few rewards, especially as their independence from the Democratic party expanded during the Daley era.” The Poles were punished
This is basically Pakistan, except instead of clans it’s immigrant groups voting for their own co-ethnics and jockeying for advantage. It’s a far cry from the political debates of the founding era, which were based on principles and political theory, not ethnic tribalism.