Shock and awe was the reaction to Friday’s tweet from @SpeakerPelosi: “Driven by the urgency of creating jobs & protecting #hcr, #wsr, Social Security & Medicare, I am running for Dem Leader.”

Nancy Pelosi’s bid to be minority leader was unexpected since the protocol is for a Speaker of the House, when the other party wins the majority, to leave the job and even Congress altogether, live with the loss, and let someone less of a lightning rod return the party to power.

Pelosi, however, isn’t one to follow protocol or precedent — as she explained at the
Fortune
Most Powerful Women Summit in Washington last month. When she first ran for House leadership, she told the crowd, the general reaction was: “Who said she could run?”

Bear in mind, the Speaker of the House — until Republican John Boehner takes the mantle in January — is the daughter of a tough pol who ruled Baltimore as mayor throughout her childhood. Then she was the youngest child and only girl, with six brothers. Now Pelosi is 70 years old and enjoys more than ever taking on the men. Her latest power play, in fact, is a logical next step in a five-year crusade that began with capturing the majority in Congress, continued with getting a Democrat in the White House, and peaked with passing health-care and Wall Street reforms. (She’s referring to those two wins in her Twitter declaration.)

And remarkably, Pelosi accomplished all this despite dismal voter favorability ratings — 24% according to the latest NBC/WSJ poll. “She reliably made fools out of those who underestimated her,” TIME’s Mark Halperin writes in an analysis of Pelosi’s bid to be House minority leader.

Pelosi still has a corps of avid supporters. (She won 80% of the votes in her California district last Tuesday.) But her run for Democratic leadership leaves many in her party incredulous. Even the liberal
New York Times
editorialized today that “Congressional Democrats need a new champion to stand against a tightly disciplined Republican insurgency.”

Nonetheless, Pelosi appears to have the support to be, come January, the House Democratic leader. No sweat for her that Republicans relish the notion that she will remain their punching bag. “If you throw a punch, you’d better be able to take a punch,” Pelosi told writer Nora Ephron, who interviewed her at the Fortune Summit. “I seem to thrive on it.”

Good thing the lady loves a fight — because they are likely to get nastier than ever.