Senator-elect Tammy Baldwin isn't wasting any time: Thursday, she's jumped directly into the austerity crisis debate by pressing President Obama to include a minimum 30-percent effective tax rate — favored by billionaire investor Warren Buffett — on Americans with incomes above $1 million.

(Darren Hauck/Getty Images)

While both Obama and Congressional Democrats have previously tried to bring up the Buffett Rule for debate in the Senate, there hasn't been much of a push behind the provision in the current budget talks, outside of Buffett's own vocal advocacy. In a letter co-authored with Sen. Sheldon Whitehouse (D-R.I.), Baldwin urges the president to go farther than just letting the tax breaks for incomes above $250,000 to expire, urging the adoption of Whitehouse's legislative version of the Buffett Rule, known as the Paying a Fair Share Act:

In addition to letting the Bush-era tax cuts expire for incomes above $250,000 as you have pledged to do, we believe it is imperative to enact a safeguard to ensure that the highest-earning Americans cannot subvert the progressivity of the tax code through loopholes and special rates not available to middle-class families.  In addition to serving as that safeguard, our Paying a Fair Share Act would reduce the deficit by $47 billion, helping to avoid more painful budget options. 

Obama hasn't given any indication that he'd be on board with further demands on taxes in the current budget discussions. But Baldwin's letter is a sign of the progressive tilt of the incoming class of Senate Democrats and how forthright they're already willing to be.