Boiled down to the essentials, union backing of leftist politicians is good business: Democrats push policies that benefit union bosses at the expense of employers, customers, and often the unions’ own members. This is doubly true of public unions; of course someone who gets rich taking money from government workers wants bigger government!

The case for union reform is tough to make due to Big Labor’s dishonestly political nature. Claiming to speak for all teachers/mechanics/factory workers/Middle Class Americans, unions have a rhetorical curtain thick enough to hide tens of millions in partisan spending. Democrats gain loyal constituents, union bosses get to make unsustainable promises, and corporations take the blame when jobs are cut or shipped overseas.

Take a look at this Center for Responsive Politics chart of top campaign contributors (view PDF screencap):

When Progressives respond to union reform with cries of “racist!” and every victim card in the book, keep this in mind: 3 of the 11 biggest political donors in the nation are public unions.

They’re in good Big Labor company, with 76% of SEIU (5) donations given to Democrats and each of these unions giving more than 85% of their contributions to Democrats: IBEW (9), Laborers Union (10), Teamsters (12), Carpenters & Joiners (13), CWA (14), UFCW (17), UAW (18), IAMAW (20).

Union bosses outspend by millions the corporations whose political influence they get rich demonizing. Democrats are expected to toe the union line as a matter of principle, while any Republican attempt at reform is framed as political payback. When GOP leaders are cowed into silence by this ridiculous double standard, union bosses win – and everyone else loses.

In Ohio, voters recently demonstrated their willingness to buy union talking points. This is why conservatives must work harder to inform our fellow citizens, and why 2012 is an awful time to push a state Right to Work amendment.

The chart above is one angle of what the GOP presidential candidate will be up against next year. Whenever you hear a Democrat complain about the corrupting influence of money in politics, agree with them – and then present this chart.

Follow Jason on Twitter: @jasonahart