Public support for the new healthcare law dropped significantly in October, a new survey shows, dealing a blow to the Obama administration as Republican presidential candidates keep up their pledges to repeal the president’s signature domestic legislative achievement. More than half of Americans now view the law unfavorably, according to a tracking poll by the nonpartisan Kaiser Family Foundation. And just 34% of Americans view the law favorably, the lowest level of support since the president signed the law in March 2010. Much of the decline appears to have been driven by faltering support among Democrats, just 52% of whom...