WASHINGTON - The passage of healthcare reform may have been a triumph for Barack Obama but he owes an incalculable debt to Nancy Pelosi.

The Speaker not only persuaded him to stick with the original comprehensive reform when all seemed lost, but also corralled the final votes that pushed the measure across the finish line in a bitterly divided House.

Many have been fooled by Pelosi, taking her for a flakey, Botox-boosted liberal from San Francisco, the city she has represented in Congress since 1987.

In fact she learned her trade from her father, Thomas D'Alesandro, a former Congressman and Mayor of Baltimore, and a master of old-style, big-city politics on the East Coast.

These skills have been in ample evidence throughout the year-long healthcare marathon.

When the Democrats lost their filibuster-proof majority in the Senate in January, she was instrumental in persuading Obama to stand by his initial plans without further delay.

She was strongly opposed to the scaled-down version of the reforms favoured by many White House aides, that she referred to as "kiddie care". As a colleague put it, "she knew that was like putting a Band-Aid on a broken leg".

As the showdown moved to a climax at the weekend, Rahm Emanuel, Obama's chief of staff, was spotted jogging in a Washington park while Pelosi was driving proceedings on Capitol Hill, cutting deals to win over wavering legislators, including the anti-abortion Democrats whose votes ultimately ensured victory.

She is not an inspirational orator like Obama but she is a consummate backroom operator and vote counter. Colleagues say she is remarkable for her focus and her determination.

And, they agree, she is not a politician to be on the wrong side of.

Pelosi, who celebrates her 70th birthday on Saturday, is not only the first female Speaker in history.

She now takes her place as one of the most powerful and most effective Speakers ever - whatever happens to the Democrats in midterm elections this November.