Another corporation has announced it is ending its membership in the shadowy lobbying organization, the American Legislative Exchange Council (ALEC).

Amgen, a California-based pharmaceutical company is the 31st company to drop its membership. Amgen is the world’s largest independent biotechnology firm in the world.

This has been a long, hot summer for ALEC, which has seen its corporate sponsors leave in droves since its operating structure has been scrutinized.

Amgen follows the lead of Hewlett-Packard, CVS Caremark, Deere & Co., Miller, Coors, Best Buy, Wal-Mart, Coca-Cola, PepsiCo, Kraft Foods, the Bill and Melinda Gates Foundation, Kaplan, McDonald’s, Wendy’s, Blue Cross Blue Shield, Mars, Inc., Intuit, Proctor & Gamble, Reed Elsevier, America Traffic Solutions, Arizona Public Services and the National Board for Professional Teaching Standards in leaving ALEC this summer.

You can go to the Center for Media and Democracy web site to see who is retaining its membership in ALEC.

Founded in 1973, ALEC supports free market principles and courts financial support from various foundations, including those controlled by the billionaire Koch Brothers.

ALEC is registered as a public charity, but other organizations assert that it is too entrenched in lobbying efforts and that it shouldn’t be considered as a 501 (c)(3) classification which allows it to keep its tax-exempt status while accepting grants from foundations, corporations and other donors.