No race has gotten more attention from the independent expenditure community than the race to replace Sen. Denise Ducheny. The Democratic primary between Assemblywoman Mary Salas and former Assemblyman Juan Vargas has turned into a $2 million slug fest – and there’s still two weeks to go before Election Day. But the race in SD 40 is really more than just a Democratic squabble. It’s become a test for Senate leader Darrell Steinberg, who is marshaling resources to back Salas’s bid. Leading the charge in this race is the Civil Justice Association of California, which has spent more than $900,000 on the race so far on Vargas’s behalf. Other business groups including the Chamber of Commerce-led JobsPAC has also spent a couple hundred thousand on the race. But what makes the race odd is a group of unions, led by the Association of Federal, State and Municipal Employees is also getting involved in the race – on the same side as the business groups. Calls to AFSCME were not immediately returned, but some have speculated the unions are using this race to send a message to Steinberg about recent budget cuts. What that message is, we’re not exactly sure, but we’re pretty sure the $300,000 their groups have spent on the race is a sign that they don’t like it.