(THE HILL) — Two new national polls show a slight lead for President Obama over Republican challenger Mitt Romney, but concerns over the economy continue to dominate voters’ opinions of federal politics.

The president held an eight-point lead, 50-42 percent, in a survey by Democratic poll firm Public Policy Polling released Tuesday. But a poll by a Republican-leaning firm, The Tarrance Group, gives the president a much narrow lead, besting Romney 47-46 percent.

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