Story highlights Hillary, Bill and Chelsea Clinton have 32 fundraisers scheduled this month

Clinton's campaign said they raised $15 million last month -- $5 million less than Bernie Sanders

Sanders has made Clinton's connections to big money donors, particularly on Wall Street, an issue in the Democratic race

Manchester, New Hampshire (CNN) Hillary Clinton, outraised by Bernie Sanders in January and facing a prolonged Democratic primary race against the Vermont senator, is planning an intense family fundraising spree to Democratic strongholds in February that could net millions of dollars.

Hillary, Bill and Chelsea Clinton have 32 fundraisers scheduled this month, according to invitations reviewed by CNN, a considerable investment of time for a presidential candidate who is currently locked in a tight contest with Sanders, a candidate who does most of his fundraising online.

Robby Mook, Clinton's campaign manager, admitted Thursday that Sanders outraised the Clinton campaign when he raised $20 million in January and will likely have the resources needed to campaign "into the spring." Clinton's campaign said they raised $15 million last month.

"I recognized in probably the summer of last year, when those first fundraising reports came on, that Senator Sanders was going to be able to raise a lot of money," Mook said at a Bloomberg Politics breakfast. "I believe he will have the resources to push this campaign well into the spring and we recognize this. And look, he outraised us in January."

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