Obama cut deeply into Clinton's political bedrock, splitting the support of white women almost evenly and running well among working class voters in a blue-collar battleground, according to polling place interviews.
Campaigning in Texas, Obama told a big rally: "Houston, I think we've achieved liftoff."
The economy and trade were key issues in the race. Seven in 10 voters said international trade has resulted in lost jobs in Wisconsin. Fewer than one in five said trade has created more jobs than it has lost.
Clinton is already campaigning in Ohio, where she faces a must-win situation on March 4th.
Speaking in Youngstown, she told a rally of supporters that Americans must rely on more than words, but hard work. It was a reference to Obama. She also repeated recent populist themes, saying more must be done "to get America back to work."
