ST. PAUL, Minn. — Democratic U.S. Sen. Elizabeth Warren of Massachusetts whipped up the crowds at a campaign event for Sen. Al Franken and helped Minnesota Democrats raise money for the upcoming campaign season at two events over the weekend.

U.S. Sen. Al Franken, D-Minn.

Franken's re-election campaign was making a pitch for volunteers at Macalester College in St. Paul on Saturday, and Warren is popular with the Democratic base. She stressed issues such as economic inequality, global warming and unions,

Minnesota Public Radio reported

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"I'm not going to lean back; I'm not going to whimper about what the Republicans are up to; I'm not going to whine about what they're doing in Washington. I'm going to fight back. And when I fight back, I want Al Franken beside me in this fight all the way," Warren said.

Franken won his Senate seat in 2008 by just 312 votes following a long recount process. State Sen. Julianne Ortman, businessman Mike McFadden and several other GOP candidates are vying to take on Franken in November.

Warren also keynoted the Minnesota Democratic-Farmer-Labor Party's annual Humphrey-Mondale Dinner on Saturday night to celebrate the 70th anniversary of the founding of the party, a merger of the state's Democrats with the Farmer-Labor Party.

DFL Chairman Ken Martin said in a statement that it was the second-largest fundraising event in the party's history. The party put the crowd at 2,000.