SACRAMENTO — As Californians hit the tax deadline, an independent think tank is handing voters political ammunition in an election year — the burden of funding state services has shifted from corporate to personal income taxpayers in the past two decades. And Democratic Treasurer Phil Angelides — the only gubernatorial candidate talking about closing corporate tax loopholes and taxing the wealthy — has sunk to underdog status in the polls. "New, increased and expanded corporate tax breaks and the 1996 corporate rate reduction are responsible for the decline in the share of state revenues provided by the corporate income tax,"...