If public sector unions in Wisconsin fail to defeat Governor Scott Walker’s anti-union budget proposals, not only would workers lose their rights to collective bargaining, but millions of dollars of compensation paid to union leaders and/or donated to Democratic politicians as campaign contributions could also go up in smoke.

The Center for Public Integrity (CPI) has revealed that the bosses of the nation’s largest unions earn large six-figure salaries and generous benefits (which are of course paid for by dues-paying rank-and-file union members)

Here are the ten largest unions in the country, with the salaries of their bosses, and information on campaign contributions during 2009-2010: (all data from CPI)