Republican Party election strategists have singled out Nancy Pelosi, the House of Representatives speaker, for bitter personal attack in the run-up to November elections.
The minority party has been relishing the prospect that the liberal Mrs Pelosi will lose her job if the Democrats lose the majority they have held since 2006.
The Californian Democrat, who is the third highest ranking elected official in Washington, has been branded as a "wicked witch" in an advertisement drawing on the Wizard of Oz, and also as a would be puppy-killer along the lines of Cruella de Vil from the drama 101 Dalmatians.
The first female House Speaker, Mrs Pelosi has shrugged off the attacks as all part of Washington's rough and tumble.
"If no one's talking about you, you have to wonder what you were doing," she told a women's forum. US politics, she said, requires "a suit of armour" and the ability "to take a punch".
Mrs Pelosi was prominent pushing Mr Obama's agenda through a sometimes reluctant House of Representatives, even with numerous Democratic defections.
She was the driving force behind the $800 billion stimulus plan to passage in February 2009, healthcare reform and an overhaul of Wall Street. She also pushed through an energy reform bill which has yet to pass the Senate.
But amid deep frustration at the stagnant economy and dissatisfaction with Washington's divisive, money-ridden culture, Mrs Pelosi looks certain to lose the gavel she uses to control debates, though her own San Francisco seat is not in danger.
"She's an inviting target, because she's emblematic of the Congress, and voters have very little respect now for Congress as an institution," said Darrell West, director of governance studies at the Brookings Institution think tank in Washington.
With the entire chamber up for election on Nov 2, experts forecast that the Republicans will win at least the 39 seats needed to recapture the House, and may seize as many 50.