(CNN) Nancy Pelosi's place in the history books is already secure. She will always be the first woman ever to serve as speaker of the House -- and the first woman to do so twice. She helped usher the first major overhaul of the US health care system in decades through the House. She led the efforts to retake the House majority not once but twice,

But what happens over these next few weeks in the House's impeachment efforts will shape the final chapter(s) of Pelosi's legacy in an important way, providing perhaps the biggest challenge she has faced in her time as speaker.

There's little doubt that House Democrats -- led by Pelosi -- are in the midst of an inevitable march toward making President Donald Trump just the third president in American history to be impeached by the House. Pelosi's blessing on Thursday of the drawing up of articles of impeachment -- an effort that will be run out of the House Judiciary Committee -- was the final, formal step that ensures that outcome.

But because the House will almost certainly impeach Trump, however, does not make what Pelosi has chosen to undertake -- and what it could mean for her party and the country -- a simple thing. The impeachment of a president has both in-the-moment political ramifications, longer-term political impacts and, obviously, sets precedent for how future presidents can act and how Congress should respond.

And it's important to remember that Pelosi -- as recently as a few months ago -- didn't want any of this . Despite a majority of House Democrats being publicly in favor of opening an impeachment investigation, Pelosi resisted the pressure to offer that movement her support. Her hesitancy was based on a belief that impeachment is an extreme measure, only to be used when it can be done so with bipartisan backing -- and that if it is seen as a partisan endeavor, it could badly divide the country and create a volatile and dangerous political environment.

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