Reuters: California’s governor race is shaping up to be a referendum on the most aggressive U.S. plan to cut greenhouse gases in a vote from the trend-setting state that could hobble such efforts nationwide. The state is a hub for investment in “cleantech”, which could be at risk with any policy change, and has a governor and senior congressional representatives who have led President Barack Obama’s push for a U.S. climate change law. The face-off to replace Republican Governor Arnold …