Voters drifting toward Clinton before crucial vote next week

Washington: Polls showed voters drifting toward Hillary Rodham Clinton before crucial Democratic primary votes next week, but the all-important party superdelegates - whose backing is now essential for the nomination - were falling increasingly in line behind Barack Obama.

Despite the momentum building behind Clinton after her win in Pennsylvania, it still appeared mathematically impossible for her to overcome Obama's delegate lead for the party nomination.

Clinton has a 20-superdelegate lead, 268-248, but Obama holds the overall advantage in delegates, including committed superdelegates, 1,736.5-1,602.5.

That means the superdelegates, the nearly 800 party officials and office holders free to back either candidate regardless of state votes, will decide the nominee. So far 516 have chosen sides.

Regardless, Clinton appeared to be gaining strength among voters, especially the white working-class which has reacted negatively to Obama's association with Reverend Jeremiah Wright - the Illinois senator's former pastor who called from the pulpit for God to damn America for it's treatment of African Americans.

Reflecting that shift, a poll released on Thursday by Pew Research Center for the People & the Press showed Clinton's lead over Obama nationally among whites who did not attend college had increased from 10 points in March to 40 points at the end of April.

Pre-vote surveys

That voting bloc played heavily in Clinton's substantial win last week in Pennsylvania and was likely to be just as critical on Tuesday, when voters cast ballots in Indiana. Pre-vote surveys there showed the outcome was a toss-up.

A second poll released on Thursday carried more potential bad news for Obama, this in North Carolina, which votes in tandem with Indiana.

The Mason-Dixon Polling & Research Inc. survey for two television stations in the state showed Obama's double-digit lead had slipped to just seven points, 49-42.

Nationwide, the Pew poll showed, Democratic voters now are about evenly divided, with Obama holding a statistically insignificant 47-45 margin. In late March he was up 10 points, 49-39.

The latest Gallup tracking survey had Clinton leading 49-45, after a week of showing them nearly even. Obama held a 10-percentage point margin going into Pennsylvania.