CARSON CITY, Nev. (AP) - Democrats hold slim margins in the Nevada Senate and Assembly, but halfway through the 2011 session it's Republican Gov. Brian Sandoval and the GOP minority who are holding the trump cards. Elected on a no tax platform, the governor has pledged to balance the state budget with existing revenue - and deep cuts to education and social programs.Democrats, while conceding painful cuts are inevitable, have been trying to rally public outcry to try to force their counterparts to consider taxes. But they lack a two-thirds voting bloc necessary to pass tax or fee hikes or …