The haul surpassed his totals from the first and second quarters of 2019 combined, and nearly matched his third quarter total of $25.3 million. He led the Democratic primary field with $34.5 million in contributions over the final three months of the year.

Sanders' campaign spent $50 million during the final quarter of 2019, exceeding its intake, but still began January with $18.2 million in cash-on-hand. His January fundraising figures underscore the enduring power of his grassroots donor base, which will allow him to compete -- and spend big -- deep into what could be a long and expensive primary contest.

With big states like California, which votes on Super Tuesday in March, on the horizon, the new money will be crucial in paying for pricey television ad time and a large field operation at a time when billionaire Michael Bloomberg is already spending at an unprecedented clip.

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