Editor’s Note: Julian Zelizer, a CNN political analyst, is a professor of history and public affairs at Princeton University and author of the forthcoming book, “Burning Down the House: Newt Gingrich, the Fall of a Speaker, and the Rise of the New Republican Party.” Follow him on Twitter: @julianzelizer. The views expressed in this commentary are his own. View more opinion at CNN.

CNN  — 

House Speaker Nancy Pelosi has brought the impeachment inquiry to its final phase. In her press conference Thursday morning, she announced that the Judiciary Committee will begin drafting articles of impeachment.

Unless a large number of Democrats break from the Speaker, President Trump will join Andrew Johnson and Bill Clinton as the only presidents who have been formally impeached by the House. From the perspective of presidential history, this will become a major part of how we remember the term.

With a firm hand and clear vision, Speaker Pelosi has done something that no one else seemed to be able to accomplish. She has seized back the public square from the Trump White House. For the first two years of the administration, Democrats struggled to focus any discussion as the President and his tweets and scandals constantly sent the media chasing the latest shiny objects.

Democrats often seemed incapable of responding. Without control of the House, they were in a perpetual struggle to move the discussion away from the chaos and fog and toward the most pressing issues.

But the 2018 midterms changed the power balance, and Speaker Pelosi has used her power well. After vacillating over fears of an anti-impeachment backlash, Pelosi instructed the Intelligence Committee and now the Judiciary Committee to move forward.

Now, after spending several months laying bare to the public how the President used his power for personal political advantage and blocked efforts to uncover the truth – abusing his office and obstructing justice – the House will formalize the charges against him. In doing so, Democrats will make a collective statement fulfilling their constitutional obligation to say that this President is corrupt, abusive and dangerous to the national interest.

By shaping the debate in this fashion, Democrats have thrown new light on everything that goes on in and around the White House, such as the current overseas trip of Trump’s personal lawyer Rudy Giuliani, meeting with a former Ukraine prosecutor seeking an investigation into Biden.

Even though Senate Republicans will probably not join a vote to convict and remove the President, Speaker Pelosi will have made the case with greater clarity and force than Trump ever could have imagined. She has explained why so many Democrats see this President as such a dangerous presence in Washington, and why some Republicans are privately fearful of what is happening. Democrats will put in an official vote to state that they believe Trump should no longer serve.

While polls show that most Republicans remain supportive of the President, national polls tell a different story. More Americans believe that the President is deserving of impeachment and being removed than was true with President Richard Nixon in the final months of his presidency.

This will be the major issue of the 2020 campaign. Of course, other national issues will help determine the kind of candidate Democrats select. But more important than anything else facing the electorate will be this: Can our democracy withstand four more years of Trump? As a result of Speaker Pelosi’s determination, Democrats will make their answer very clear – and Republicans, by voting to protect the President, will make their position clear as well.

For all the talk of an Imperial Presidency, Speaker Pelosi has just reminded Americans that when they have the power and the will, congressional majorities can still respond with force and vigor to a President who listens to no one.