Obama rolls forward after three big U.S. wins

By Andrew Stern

JANESVILLE, Wis. (Reuters) - Riding a string of overwhelming victories, Democrat Barack Obama turned his focus on the ailing U.S. economy on Wednesday while his rival Hillary Clinton looked ahead to contests next month where she hopes to regain her edge.

Obama and Republican front-runner John McCain cruised to victories in Virginia, Maryland and the District of Columbia on Tuesday, with McCain moving closer to clinching his party's nomination for the November election.

Obama, who extended his hot streak to eight straight wins over Clinton in a hard-fought presidential campaign that appears to be tipping his way, focused on the economy in a speech at a General Motors plant.

"We are not standing on the brink of recession due to forces beyond our control," Obama said in remarks prepared for delivery. "It was a failure of leadership and imagination in Washington -- the culmination of decades of decisions that were made or put off without regard to the realities of a global economy."

While Obama campaigned in Wisconsin, which votes next week, Clinton focused on contests in the heavily populated states of Ohio and Texas in three weeks as her best hope to stop Obama's surge.

Tuesday's victories allowed Obama to expand his lead in pledged convention delegates, who will select the Democratic Party's nominee at its August convention.

The former first lady, who would be the first female president, flew to El Paso before the votes were counted on Tuesday night and was spending the day campaigning in Texas. She also launched a series of new ads aimed at Ohio and Texas.

Clinton focused part of her effort on courting Hispanics, a demographic she considers more in her camp than in Obama's.