SEAL BEACH, Calif. ( TheStreet) -- Politics is always a volatile factor when it comes to moving stocks either up or down, and Clean Energy Fuels ( CLNE) was feeling the negative pressure on Monday. The stalled climate bill in Washington D.C. was the reason for the volatile trading in Clean Energy Fuels shares. Clean Energy Fuels is a supplier of natural gas and natural gas fueling stations for natural gas powered vehicles. Clean Energy Fuels is a notable alternative energy play of T. Boone Pickens, who is the largest shareholder in the stock. Shares of Clean Energy Fuels were down close to 9% at midday Monday. Trading in Clean Energy Fuels shares had already passed its average volume of just under two million shares by the midday mark on Monday also. On last Thursday and Friday, shares of Clean Energy Fuels ran up as it looked like a climate bill was set to be debuted by the Senate this week. The bill is expected to include a subsidy for public and private vehicle fleets that make the move to natural-gas powered vehicles. Yet over the weekend, the major Republic sponsor of the bill, Sen. Linsdey Graham (R-S.C.), said he was pulling his support as a result of Senate majority leader Harry Reid's decision to put immigration at the top of the Senate's agenda. The political chess game in Washington D.C. hit shares of Clean Energy Fuels hard as its rally last week was predicated on the quick introduction of a climate bill including a subsidy for natural gas vehicles. T. Boone Pickens had previously stated that a bill would be passed before Memorial Day, helping to fuel a run up in natural gas vehicle stocks. A bill with 140 co-sponsors that would provide a subsidy for natural gas vehicles making the vehicles as inexpensive as conventional fuel vehicles was expected to be added to the climate bill as a way to get the political powers-that-be to stomach the cost of subsidizing the natural gas vehicle market. Otherwise, a stand-alone natural gas vehicle subsidy would encounter resistance in a federal political atmosphere dominated by the rhetoric of cutting costs.