Tom Steyer, the liberal billionaire who bankrolled opposition to the Keystone XL oil pipeline, has turned his sights on ExxonMobil, and is using his well-funded super PAC to push New Hampshire's attorney general to investigate the oil company.
It's been nearly one decade since former Vice President Al Gore released his film "An Inconvenient Truth." It sent shockwaves through American politics and emboldened environmental activists to push for more regulations on American businesses.
