US Democratic presidential candidate Hillary Clinton has dismissed the 'elite opinion' of economists who criticised her gas tax proposal, using a term that has dogged rival Barack Obama in recent weeks.
Senator Obama, meanwhile, accused the New York senator of pandering on gas taxes and sabre-rattling toward Iran as both candidates gave television interviews before primary contests in North Carolina and Indiana.
Senator Clinton used her appearance on ABC's This Week to raise questions about Senator Obama's ability to connect with working-class Americans while dismissing economists who have said her plan to suspend gas taxes over the summer would do little good.
Critics have painted Barack Obama as elitist for a comment he made about job losses causing some small-town Americans to become bitter and to cling to guns and religion.
That perception hurt the Illinois senator in the big blue-collar state of Pennsylvania, where Senator Clinton won a crucial victory last month in the protracted Democratic contest.
The two candidates next square off in North Carolina and Indiana on Tuesday.
In an interview on NBC's Meet the Press, Senator Obama dismissed Hillary Clinton's gas-tax proposal as a classic Washington gimmick that has no chance of becoming law.
He acknowledged he should have more quickly distanced himself from his former pastor, the Rev Jeremiah Wright, who has suggested the US government created AIDS to kill blacks and the 11 September 2001 attacks were payback for US foreign policy.
Senator Obama did not repudiate Rev Wright completely until last week, after the Chicago preacher reiterated his views.
The Illinois senator also compared Hillary Clinton's views on Iran to those of unpopular Republican President George W Bush.
Senator Clinton has threatened to 'totally obliterate' Iran if it attacked Israel.
Senator Obama remains the front-runner in the Democratic race, though he is not expected to win enough delegates from state contests to clinch the nomination outright. The nominee is likely to be determined by party insiders.
Opinion polls show Barack Obama losing ground to Hillary Clinton in Indiana and North Carolina during the past several weeks.
He now leads Senator Clinton by an average of seven points in North Carolina and trails her by an average of six points in Indiana.
On Saturday Senator Obama eked out a narrow seven-vote victory in the US Pacific island territory of Guam.
He finished with 2,264 votes against 2,257 for Senator Clinton. Neither of the candidates has campaigned in Guam, which has just four delegate votes.
Analysts say it will barely register in their duel for the Democratic party's presidential ticket.
