( March 1, 2012) -- Sen. Herb Kohl (D-Wisc.) is a persistent man. On Feb. 28, he introduced an amendment to the Senate Sur face Transportation Bill to permit the Department of Justice to sue the Organization of Petroleum Exporting Countries (OPEC) for collusive practices in setting the price or limiting the production of oil. The so-called NOPEC amendment (“No Oil Producing & Exporting Cartels”) has been a goal of Kohl for more than 20 years and, with his retirement looming later this year, he shows no signs of giving up....