The Employee Free Choice Act has galvanized business lobbies like nothing else in recent years. After all, most issues–say, trade–pits one business lobby against another but few issues unite them. So it’s interesting and notable to say the least that one of the most talked-about parts of business is staying out of the EFCA debate: the trade group representing private equity firms like the Carlyle Group and BlackRock. On one hand you would think that private equity firms would have a particularly big stake in fighting EFCA. After all, they often buy businesses under the assumption that they keep the unions out. The Service Employees International Union, for instance, fought the Carlyle Group’s takeover of Manor Health Care, a chair of assisted living facilities. . It ultimately failed but it’s still trying to organize the chain’s workers. Dunkin Donuts is owned by a partnership of Bain Capital, Mitt Romney’s old firm, the Carlyle Group and Thomas H. Lee Partners. But the main voice of private equity firms in Washington, the Private Equity Council, has stayed out of the fight and the answer would seem to be owing to the fact that unions provide so much capital to private equity. In fact, the Private Equity Council’s own research shows in 2007 alone,” the top 20 public pension funds, representing nearly 10 million retirees in states including California, New York, Texas, Florida, New Jersey, Ohio, Pennsylvania and Michigan, had a collective private equity investment of nearly $140 billion.” This is a long way, of course, from getting Steve Schwarzman or Henry Kravis or David Rubenstein to support EFCA. But at least, as unions press forward with EFCA, they don’t have private equity’s trade group joining the rest of the business lobby.