The Democratic Senatorial Campaign Committee has posted another record fundraising month, the committee announced Thursday, padding its war chest further for a fiercely competitive midterm election cycle.

The committee brought in $6.8 million last month -- its best February ever -- to bring its total raised this cycle to $66 million. The campaign arm set up to defend Democratic candidates for Senate finished the month with $18.1 million on hand and $1.2 million in debt.

The DSCC has so far been outpacing its Republican counterpart, the National Republican Senatorial Committee. But Senate Democrats will need every dollar and more to compete with big-spending pro-Republican outside groups, which are focused intently on winning the Senate for the GOP this cycle.

Among those groups, Democrats have recently taken public aim at Americans For Prosperity, a group funded in large part by the billionaires David and Charles Koch that has already spent more than $30 million on advertising in battleground states. To raise money and energize their base, Democrats have set out to make the Kochs a campaign issue, charging that Republican candidates are "addicted to Koch."

“Across the country Republican Senate candidates are embracing a dangerous agenda that’s good for billionaires like the Koch Brothers and bad for nearly everyone else in the country," said DSCC Executive Director Guy Cecil.

The DSCC will also need to raise a hefty sum this cycle to fund a new voter-turnout scheme, the Bannock Street Project, to mold the electorate to fit the shape of a presidential-election year, which tends to favor Democrats. The DSCC has estimated the project will cost roughly $60 million.

"We know our biggest challenge in the midterms is turnout, and we need our supporters to continue to help us win each month so we can provide our campaigns with cover on television and fund the most aggressive field effort in history," Cecil said.

The stakes could not be higher for Democrats, who are at risk of losing their six-seat majority in the Senate — and the sense of urgency is growing. Republicans have in recent weeks expanded the battleground map to include states such as Colorado and New Hampshire, signaling confidence among the GOP that the president's low approval rating and public dissatisfaction with Obamacare will drive a Republican wave at the polls.