With change versus experience emerging as the touchstone in this year's presidential battle, Mr Obama's 12-point advantage (52 per cent to 40 per cent) over Mr McCain doubled Mrs Clinton's six-point margin (50 to 44) against the Arizona senator, according to an ABC/Washington Post poll.

The survey, carried out prior to Mrs Clinton's dramatic Tuesday victories in three of four primary contests including the delegate-heavy states of Ohio and Texas, showed Mr Obama losing out to Mr McCain on experience (19 to 70 per cent) and in knowledge of world affairs (24 to 64 per cent).

But the 46-year-old Illinois senator came out ahead of Mr McCain 53-32 per cent on who was thought to have a clearer vision for the future, as well as on who was better positioned to bring about change (56 to 31 per cent).

With his hard line on security and his vow to stay the course in Iraq where Democrats promise troop withdrawals, Mr McCain inspired more confidence among respondents than Mr Obama on the question of fighting terrorism (58 to 33), and he held a slimmer lead when it came to the war in Iraq (48 to 43).

Mr Obama however carried respondents on the issues of the economy (49 to 37), immigration (48 to 35) and health care (56 to 30).

Overall, poll results showed Mr Obama as more capable than Mrs Clinton of pilfering votes away from the Republican electorate in November, with 16 per cent of Republicans saying they could vote for Mr Obama compared to nine per cent for Mrs Clinton.

The poll reflected the understanding that Mr McCain lacks support among some social conservatives, with 30 to 33 per cent of conservatives saying they would vote for Mr Obama or Mrs Clinton rather than McCain.

The poll of 1,126 adults was conducted from Feb 28 to March 2 by telephone and has a three-point margin of error. -- AFP