(CNN) -- Following his trouncing in West Virginia, Sen. Barack Obama headed to Michigan on Wednesday to woo the voters who have been hesitant to embrace his candidacy.
He also directed his rhetorical fire at Sen. John McCain, the presumptive Republican presidential nominee, rather than his rival for the Democratic presidential nomination, Sen. Hillary Clinton.
With a comfortable lead in the overall delegate count, Obama is setting his sights on swing states that could pose problems for him in the fall.
Next week, Obama heads to the critical general election state of Florida.
During a stop in Warren, Michigan, Obama blasted McCain for not offering policies that would help to revitalize an area hard hit by the decline of the domestic auto industry.
"When McCain came to Michigan in January, he said we couldn't bring back all the jobs that have been lost back to America. He was right. We can't bring back every single job," Obama said.
"Where he was wrong was in not offering policies and new solutions that are different than what George Bush has been offering over the past seven and a half years," he said. "That was wrong."
Obama also outlined his plan to bolster domestic manufacturing and create jobs.
"It's time to recapture the spirit of innovation that has always fueled America's economic success," he said.
"It's time we had an economy that was driven not just by foreign debt, but by the power of America's imagination. It's time to tap the ingenuity of engineers and entrepreneurs, policy experts and working folks to meet the challenges of our time." Watch Obama on the campaign trail »
Warren lies in Macomb County, home of the original "Reagan Democrats."
The Reagan Democrats were blue-collar voters who crossed party lines in the early 1980s to support Ronald Reagan, a Republican, because they thought he would do a better job protecting the working class.
Many Reagan Democrats have continued to defect from Democrats in national elections.
George Bush carried Macomb County in 2004 even though John Kerry narrowly took the state of Michigan.
White, blue-collar voters have overwhelmingly flocked to Clinton throughout the primary season, as they did Tuesday in West Virginia, where Clinton won by 41 percentage points.
In West Virginia, Clinton defeated Obama by 50 percentage points among white voters without a college degree. Among white voters making less than $30,000 a year, Clinton's margin of victory was more than 60 percentage points.
In previous contests, Obama has been more successful with affluent, well-educated voters across the board and among African-Americans.
Clinton trails Obama across all fronts -- pledged delegates, superdelegates and the popular vote.
Despite calls to drop out and a campaign that's $20 million in the red, Clinton on Tuesday vowed to push forward. Watch how Clinton's win could affect the race »
"I am more determined than ever to carry on this campaign," she told supporters in Charleston, West Virginia.
Clinton is backing up her argument by focusing on her wins in key swing states like West Virginia, Ohio and Pennsylvania. She also touts her victories in Michigan and Florida, but those states were stripped of their delegates for holding their primaries too early, and Obama didn't even have his name on the ballot in Michigan.
However, with only 28 delegates at stake in West Virginia, Clinton's huge win did little to cut into Obama's lead.
And a new Quinnipiac poll released Wednesday, however, suggests that both Democratic candidates could beat McCain in a general election. In the poll, Obama led McCain 47 percent to 40 percent, and Clinton led McCain 46 percent to 41 percent.
The Quinnipiac poll has a margin of error of plus or minus 2.4 percentage points. It was conducted May 8-12.
Clinton's campaign is trying to turn out the vote in the final five contests in an effort to catch Obama in the popular vote.
Clinton on Wednesday met with committed and uncommitted superdelegates, sources inside the campaign said. Clinton was expected to assure them she is staying in the race. Campaign sources said fundraising picked up following her West Virginia win.
The campaign trail moves to Kentucky and Oregon, which vote next Tuesday. Clinton is expected to do well in Kentucky, where her working-class message carries a lot of weight, but Obama is the favorite to win Oregon.
A Portland Tribune and KPTV poll released Wednesday has Obama leading Clinton by 20 points in Oregon, 55 percent to 35 percent. Ten percent of the voters were unsure.
The Tribune/KPTV poll was conducted May 8-10, before Clinton's victory in West Virginia. The poll had a margin of error of plus or minus 4.8 percentage points.
CNN's Alan Silverleib contributed to this report.