A new poll shows that Proposition 15, the property tax increase initiative on the November ballot, is losing popularity with likely voters. A Public Policy Institute of California (PPIC) poll released September 17 showed that voter support for Proposition 15 is barely above 50 percent and has fallen in recent months. The PPIC poll found that even after being subjected to more than a year of misleading campaigning by public employee unions, only 51 percent of likely voters say they support…