Antonio Weiss's loss was Elizabeth Warren's gain. The would-be Treasury Department nominee ended up on the wrong side of the liberal Massachusetts senator and pulled his name from consideration.

Joining with other progressives, Warren objected to Weiss's close ties to Wall Street and what those connections might mean for bank regulations and oversight.

In a letter written to President Obama, first obtained by Politico, Weiss, an investment banker, bowed out:

I am writing to request that the administration not re-submit my nomination. I do not believe that the Treasury Department would be well served by the lengthy confirmation process my renomination would likely entail.

More like bloody confirmation process, with Warren leading an emboldened band of progressives who have little governing muscle but can gum up the nomination process.  This is the Warren way.

It happened before with Larry Summers, Obama's pick to lead the Federal Reserve. He drew the ire of Warren and other Democrats and subsequently pulled his name from consideration. (Warren wanted Janet Yellen at the Federal Reserve, and she got Janet Yellen.)

These are the fights that progressives lost in 2008, when Obama picked a slew of Clinton-era financial advisers. And it remains one of the biggest sore spots for progressives, driving a sense of buyer's remorse that makes Warren's rhetoric such a draw for them.

Warren's November op-ed on Weiss, titled "Enough is Enough: The President's Latest Wall Street Nominee," sums up the progressive view. Now because of Warren's focused fight, progressives are notching small victories, dooming Obama's hand-picked financial advisers who they see as soft on regulation and too cozy with Wall Street.

With these moves, Warren is showing how she will be a player in 2016 and beyond.  There aren't any signs she will run, and there is also little evidence that she could outflank Hillary Clinton with the Obama coalition. But she will be a hard-liner on financial issues, vetting Clinton's campaign picks, just as she did with Weiss and Summers.

It's not hard to see Warren making herself into a kind of shadow financial adviser for Clinton. Her tacit stamp of approval would inform not only her rhetoric but who Clinton surrounds herself with. (Obama is surely thinking about a Warren-proof nominee for the Treasury post).

Because Warren has shown that even when she's on your side, there is no end to the tough questions: