Senate Democrats narrowly pushed through a measure to extend tax rates for family income up to $250,000 for a year, as both parties continued their election-year messaging war on taxes.

By a 51-48 tally, Democrats overcame two defections to win passage of a measure that would also raise the top rate on capital gains and dividends, as well as continue several targeted tax provisions that Democrats say help the middle class.

Vice President Biden presided over the tally. He was in the Senate chamber in case his vote, as president of the Senate, was needed to break a tie.