Chicago: Democrat Barack Obama expressed frustration today that racial issues keep rising to the top of his presidential battle with Hillary Rodham Clinton, but he said the great majority of voters will base their decisions on substantive issues.

At a news conference in Chicago, Obama said he feels his primary victories in an array of states have proven he can draw support from all races and regions, and that he is not overly reliant on black support.

"We keep on thinking we ve dispelled this," he said. "And it keeps on getting raised once again."

He said critics suggest "maybe he hasn t proven that he can win white blue-collar workers."

"And we won that in Virginia, and we won it in Wisconsin," he said.

In each new primary, he said, "we seem to have to prove this stuff all over." Given his wins, he said, "at this point, we should have put to rest this notion that somehow I am a candidate that s just focused on one demographic."

In handily winning the Mississippi primary on Tuesday, Obama took about 90 per cent of the black vote and 30 per cent of the white vote, according to exit polls. Similar results in other Deep South states have raised questions of whether Obama s strong black support is nudging some white Democrats into Clinton s column.

There was some evidence of that in exit polls in Ohio, which Clinton won. Analysts say a similar pattern could emerge in Pennsylvania, the next primary, on April 22.

Source : PTI