Alex Pareene explains that the traditional political understanding of presidential politics doesn't apply to Elizabeth Warren. It's not about a clash of personalities, and it's not a recasting of 2008's Clinton vs. Obama fight. It's about the party:
The point of arguing for more “economic populism” isn’t necessarily to take down Hillary Clinton in 2016, though I’d certainly rather have a President Warren than another President Clinton. (Though — and I say this as a Warren admirer — she’s kind of a blank slate on non-finance issues, right?) Clinton isn’t quite inevitable, but aiming immediately for the presidency is in many respects reaching for a symbolic victory before achieving anything substantial. The point of “economic populism” is to fix the Democratic Party at every level.
The trick, of course, is to fix the Democratic Party without descending into a leftward version of the Republican Party's current teabaggy hell for the next decade. I think it's absolutely possible to promote economic populism in such a way that doesn't turn off independents and moderates. It's not easy, but it's possible.