* Poll shows most Democrats support legalization * Republicans strongly against, independents divided * Prop. 19 would let local governments regulate sales By Peter Henderson SAN FRANCISCO, Oct 5 (Reuters) - Hopes that California will become the first state in the nation to legalize marijuana appear to be turning into a pipe dream. Voters plan to oppose a measure on the Nov. 2 ballot to legalize marijuana use by 53 percent to 43 percent, according to a Reuters/Ipsos poll released on Tuesday that showed a big change of sentiment from June. [ID:nN05207672]