The New York Times reports:
Mr. Santorum easily defeated Mr. Romney on Tuesday in Tennessee, a Southern victory that would help him make the case for continuing to contest Mr. Romney for the Republican presidential nomination.
Mr. Santorum's campaign had focused much of its attention in the past week on Ohio. But with Mr. Romney all but certain to capture several other states, Mr. Santorum also pushed hard for wins in the South.
By emerging victorious in Tennessee, Mr. Santorum stopped Mr. Romney in a state where aides to the former Massachusetts governor had thought he might do well.