"I learned a long time ago not to bet against Nancy Pelosi," John Lawrence told DW in a recent interview when asked to size up the coming clash between President Donald Trump and House Speaker Nancy Pelosi, which many observers think will shape the political landscape in the US over the next two years.        

Lawrence should know. He worked for almost four decades as a senior Congressional staffer on Capitol Hill, the last eight years as chief of staff to Nancy Pelosi. And while Pelosi, who is 78, and Trump, who is 72, are peers, they are separated by a gulf of political experience.

"She has a vastly better sense of the political system than Mr. Trump," said Lawrence, who worked as Pelosi's top aide from 2005 to 2011. "I think Mr. Trump — I have not worked with him — but those of us who follow politics pretty closely see in Mr. Trump somebody who fundamentally misunderstands the allocation of power in the American political system."

Despite not having won the popular vote in the presidential election, added Lawrence, Trump appears to believe that he was "anointed to have much greater power than presidents have in the modern American government."

Historic figure   

Trump's apparent belief in what has been called an imperial presidency first clashed with the new political reality of a divided government when the house speaker effectively postponed the president's traditional State of the Union address before Congress until the government shutdown is over. After initially vowing to give his address at a different location, Trump quickly backed down and accepted Pelosi's postponement.

Read more: Opinion: Trump's Oval Office address was a missed opportunity

While the showdown between Trump and Pelosi — who as Speaker of the House of Representatives is second in line for the presidency after the vice president — over the largely ceremonial State of the Union address has little practical consequences, it delivered a clear message to Trump that Pelosi is keenly aware of her constitutional powers and is not afraid to use them vis-a-vis the president.

"She is speaker of the House — a constitutional officer with authority independent of the president to control access to the Capitol," said Thomas Mann, who studies Congress for the Brookings Institution. He described Pelosi as a professional colleague he has known for 25 years. "She is smart, politically savvy and tough, and she leads a united party."

Pelosi made history when she became the first female speaker of the House of Representatives in 2007, and again this year when she became the first speaker in more than 50 years to reclaim the position after losing it.

While it may seem that Pelosi's political path was predetermined, particularly because she hails from a political family in Baltimore where both her father and her brother served as mayor, her political rise was unorthodox. Pelosi, who moved to California with her husband and raised five children, only devoted herself full-time to politics when she was in her forties after all her children had left home. She first ran and won a House seat in a safe Democratic district in 1987 and has held on to it ever since, thereby quickly moving up the ranks in Congress.           

Her most significant achievement during her tenure as Democratic leader in the House of Representatives was working with Republican President George W. Bush during the financial crisis in 2008 and preventing a total economic meltdown, said Mann and Lawrence.

Read more: Trump administration downgrades EU mission to US

Independence from Obama White House

Both also credit her leadership for ensuring the passage of then-President Obama's historic health care legislation, known as the Affordable Care Act. To achieve that, said Lawrence, Pelosi was prepared to go head-to-head with Obama White House advisers if necessary.    

"I certainly remember when we were in the Oval Office with President Obama and we were talking about the health care law. And there were people that she was aware of on the president's staff who were suggesting that this had become too difficult and that, if we didn't roll back the scope of the bill that we were talking about, that we would get nothing and that we should just fold our tent and accept a very small bill and hopefully live to fight another day on a big national health insurance bill," said Lawrence.

Read more: Two years in, Trump remains the 'unprecedented president'

But Pelosi, "in no uncertain terms, told the president and his staff that she would not accept that, and that the House was committed to going ahead with a tough bill even if it meant a very tough fight, and even if it meant that some members were going to be put in political jeopardy," said Lawrence. Her insistence effectively ended any attempts to water down the scope of the signature bill, which eventually passed.

Trump faces steep learning curve

The showdown in Obama's Oval Office highlights Pelosi's view of her role as the representative of a co-equal branch of government that is on par with the president, noted the experts.  

Due to a deferential, Republican-led Congress, President Trump has obviously not learned in his first two years that Congress is a co-equal branch of government, said Lawrence. "But he is going to learn that now," he added, "because he has a very skilled opponent in Mrs. Pelosi and he has a party in control of the House which simply is not going to defer to his will."

Citing a mercurial president, Lawrence and Mann avoided making predictions about whether Trump or Pelosi might have the upper hand in what both considered the signature political fight of the next two years.  

"If Trump is prepared to blow up his party, his re-election and the country, he does. If not, she does," offered Mann.

Each evening at 1830 UTC, DW's editors send out a selection of the day's hard news and quality feature journalism. You can sign up to receive it directly here.