SACRAMENTO - Gov. Arnold Schwarzenegger on Wednesday is expected to sign into law the United States' first state cap on greenhouse gas emissions, after striking a deal with legislative Democrats that brought California and the governor global publicity. But even before the bill is signed, the law's future is in doubt. Federal lawsuits related to greenhouse gas issues, involving California, Vermont and Massachusetts, could cloud California's latest attempt to be a leader in the fight against global climate change. At the heart of California's attempt to curb the gases believed responsible for global warming are state auto regulations that are...