Looks like another one of those "extreme special interests" is getting involved in the senate race between Sen. Blanche Lincoln and Lt. Gov. Bill Halter. The Sierra Club launched a series of radio ads today, taking Lincoln to task for her environmental record. Have a listen. The ad doesn't mention Halter, who was non-commital on cap and trade at his press conference yesterday. Lincoln says she opposed cap and trade legislation because it's not the best way to curb emissions and protect the environment.