The Left collects front groups the way that some people collect ships in bottles or collectible plates. It is hard to imagine the Left without its array of front groups, because the front group has been one of the biggest and most successful tactics of the Left.(full story at frontpagemag.com)
Front groups are a way of life for the Left, because, like most extremist movements whose real views would be too unappetizing for even most of its supporters, it has to disguise its true beliefs. Its army of front groups allows the Left to co-opt moderates and then filter them through its front groups to extract the true believers. Additionally the segmentation of an endless array of front groups allows the Left to target very specific demographics and organize their independent-seeming groups together into a large movement.
These techniques were used to great effect by the American Communist Party in the 1930s and by the Obama 2012 campaign.
Dig into the Left and you emerge in that same hall of mirrors where every organization is a front for another organization, where grant money is passed along through a complex network of activist groups, family foundations and assorted non-profits that share office space and web servers with some of the same organizations that they fund, where staffers move back and forth from running the organizations that they fund to funding the organizations that they run.