Speaker Nancy Pelosi will relinquish the gavel to the perpetually tanned, lachrymose Republican leader John Boehner when the new Congress convenes next January. It will be four years after that January 4, 2007 day when she “broke the marble ceiling” and became the first woman Speaker in the two-century history of the House.

At the time, Republican pundits mocked Democrats for the choice of a “San Francisco liberal” woman as speaker, suggesting she’d be a weak leader, unable to control the conservatives in the ever disputatious Democratic party, and easy to burlesque in campaigns across the country.

But this was Nancy Patricia D’Alesandro Pelosi, raised in a tough Baltimore Italian political family, who imbibed politics with her mother’s milk. Republicans soon discovered that Democrats had chosen not just the most progressive, but also the most effective and powerful speaker in memory.

She was disciplined, shepherding her flock of progressives, Blue Dogs, New Dems, blacks, Latinos, women and good old boys, to focus on core issues — the kitchen table concerns that Americans worry over every night at home, the challenge to George Bush’s disastrous wars abroad. She was tireless, intent on consolidating her majority and helping Democrats to take the White House. She was practical, raising record sums of money in fundraisers across the country, the necessary coin of America’s debauched politics. She was tough, getting members to take votes they wanted to duck, forging the majorities she need to overcome unified Republican opposition. And she was, for better and worse, independent, willing to block the left’s efforts to impeach the president or end funding for the war that she thought would be damaging electorally.

In the face of the Bush White House and launch of the Republican strategy of obstruction through misuse of the filibuster, Pelosi produced far more in her first term as Speaker than anyone expected; far more, for example, than the much ballyhooed Gingrich Contract with America Congress in 1995-96.

The Pelosi-driven Congress increased the minimum wage, expanded investment in education and college, passed a bold new GI bill for veterans, passed lobbying and ethics reform, enacted many of the recommendations of the 9/11 Commission, and made headway on new energy, childrens’ health care, college loans, Head Start, and more — much running afoul the mosh pit of the Senate and some the veto of the president.

Liberals were livid that the House failed to cut off funding for the Iraq War, with many of the Blue Dog candidates of former Democratic Congressional Campaign Committee head Rahm Emanuel getting in the way. But Pelosi’s Democrats kept the pressure on, setting up timetables and reporting deadlines that made it clear it was time to declare victory and get out.

With the election of Barack Obama and the consolidation of her majority, Pelosi demonstrated her remarkable leadership. The swing votes in the House came from largely conservative Democrats elected in districts that voted for John McCain. Yet, time and again, in the face of unified Republican opposition, Pelosi rallied her caucus to pass historic legislation — the largest recovery act ever, the largest increase in student aid ever, comprehensive health care reform, comprehensive energy legislation, financial reform, and more. She asked her members to take tough votes and they responded. Too often, she was then hung out to dry by a passive White House and an obstructionist Senate that diluted, delayed and defeated major reforms.

Her true grit was demonstrated in the fight over health care. After Scott Brown’s stunning victory for Sen. Edward Kennedy’s Senate seat in Massachusetts, many in the White House and the Congress assumed comprehensive reform was dead. Pelosi would not accept retreat or defeat, and wouldn’t allow the White House to go wobbly on her. The lady was not for turning. Inane White House strategy — dithering for months with Max Baucus, for example — made the bill far weaker than it had to be, but the result was an historic accomplishment.

The best measure of Pelosi’s stature — and her achievement as a woman in leadership — was that Republicans joined her with the president as their poster targets in the election. With hundreds of hours of ads vilifying her without any effective rebuttal, her popularity plummeted, her “negatives” soared. Democrats were held accountable for failing to revive the economy that conservative policies had taken over the cliff. The recovery act — too small in conception and weakened badly in the Senate — was inadequate to the cause. With a Democratic president commanding the bully pulpit of the White House, no speaker, no matter how powerful, could drive the election message.

There is no need to idealize her. On several issues from the war to the public option, many liberals, including myself, fought against compromises Pelosi forged. But there is no doubt that she has been the most effective reform speaker since the days of the New Deal.

Starting in January, she will lead a smaller, more liberal caucus against the most right-wing majority in post-Civil War history, with a White House already showing more switch than fight. The last time she was minority leader, Pelosi helped stop President Bush’s efforts to privatize Social Security. This time she may have to lead the opposition against another president’s willingness to cut Social Security.

She will no doubt be ready to offer John Boehner tissues for his tears, even as she organizes resources and energy for regaining the majority in 2012.

So in this holiday season, as we reflect on the year past, let us afford recognition to an extraordinary leader. San Francisco liberal? You bet. Doting mother and grandmother? No doubt. Tough, proud Italian scion of a political family, daughter and brother of Baltimore mayors? Never forget. From those of us who have fought with her, beside her and behind her, a toast to the most effective Speaker of our lifetime, Nancy Pelosi.