Suzy Khimm notes an important irony: 

Despite their attacks on Romney’s firm for “putting profits above workers,” unions have ramped up their pension fund investments in private equity to record levels.

The largest public-employee pensions had 11 percent of their holdings in private-equity investments, totaling $220 billion. As it turns out, however, private equity is even more dependent on union investments than the other way around. Since 2006, “U.S. private equity firms have received approximately 26% of all fund commitments from U.S. public pension systems,” Fortune’s Dan Primack points out. That could accordingly make private-equity managers on Wall Street a bit squeamish of the Republican attacks on public-sector unions–i.e., their customers. Romney, for one, has backpedaled on any remarks suggesting that he wants to cut public-sector jobs for teachers and firefighters.