Senator Hillary Rodham Clinton snapped Barack Obama’s 12-state winning streak with a victory in the Rhode Island primary on Tuesday night, but the Democratic rivals remained locked in tight races in delegate-rich Texas and Ohio, the two key contests of the night.
CNN and NBC News called the Ohio race for Mrs. Clinton, but votes were still being counted. Early returns showed Mrs. Clinton up 57 percent to Mr. Obama’s 41 percent, with just over half the precincts reporting.
Earlier in the evening, Mr. Obama won the Vermont primary by about 22 percentage points. Mrs. Clinton had a margin of about 17 percentage points in Rhode Island.