CAMBRIDGE, Mass. (AP) — Sen. Elizabeth Warren is quickly becoming a top Democratic fundraising and campaigning powerhouse, hitting the road on behalf of candidates in key races the party will need to win to retain control of the U.S. Senate in November.

Since March, the Massachusetts Democrat has stumped for candidates in Ohio, Minnesota, Oregon, Washington and Kentucky and has trips planned this week for West Virginia and Michigan. It’s a hefty schedule for a freshman senator who not long ago was teaching law at Harvard.

Along the way, Warren has found her brand of economic populism resonating far from her home in the liberal enclave of Cambridge, Mass.

Part of Warren’s economic pitch is legislation she sponsored that would let college graduates refinance their student loans at lower interest rates, an effort blocked by Senate Republicans.

Warren found a receptive crowd during a recent campaign stop at the University of Louisville with Alison Lundergan Grimes, the Kentucky secretary of state hoping to unseat Senate Republican Leader Mitch McConnell.

Cast by critics as a typical Northeast liberal, Warren, 65, grew up in Oklahoma in a family which she said lived on “the ragged edge of the middle class” — an experience that she said helped forge a lifelong interest in advocating for working families trying to get a fair deal in an economic and political system that Warren argues is rigged against them.

Warren found herself thrust into the national political spotlight during a grueling 2012 campaign against incumbent Republican Sen. Scott Brown. It was the most expensive campaign in Massachusetts history with both candidates raking in tens of millions in donations.

Warren’s profile has made her a go-to campaigner for Democratic Senate candidates, in part because as a newer arrival on the political stage she is free of some of the political albatrosses carried by other top Democrats like President Barack Obama or Hillary Clinton

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