By the time you read this, President Donald Trump's impeachment trial will be nearing its conclusion. Because of the importance of this vote, and the historic nature of only the third presidential impeachment in our history, I want to tell you directly why I will vote to remove the president from office, and where I think we go from here.

I was reluctant to go down the path of impeachment. While I strongly disagree with the president on many issues, impeachment should be a last resort. But then I read the whistleblower report, which alleged nothing less than the president's corrupt abuse of power that had the potential to undermine the 2020 election. For me, this left us no choice but to begin an impeachment inquiry.

When the U.S. House sent the two articles of impeachment to the Senate, it became my job to "do impartial justice according to the Constitution and the law." I take that oath as seriously as anything I have ever done.

This impeachment trial has been about whether the president's corrupt abuse of power — power he used for his own personal, political benefit, while betraying the public trust — is a high crime and misdemeanor as defined by our founders in the Constitution. I believe it is. I also believe that to condone such corruption undermines the core value of our nation — that no one is above the law, including and most especially our president.

Over hundreds of hours of presentations, and thousands of pages of documents, the facts of the case were never really refuted. The president withheld security assistance and a prestigious White House meeting in an effort to pressure Ukraine to announce investigations of a political rival and a baseless conspiracy theory about the 2016 election.

Then when the House sought to investigate, the Trump administration blocked subpoenas for documents and witnesses. No president has ever categorically rejected Congress' investigative and oversight powers in this way. Not Richard Nixon. Not Bill Clinton. This obstruction fractures the balance of power between the legislative and executive branches. If we say the president can decide whether he cooperates with a congressional investigation, we are saying he is above the law.

While evidence of the president's wrongdoing is substantial, I advocated for a trial that would be fair for both sides, which means hearing from witnesses with direct knowledge of the president's actions. I am greatly disappointed that almost all my Republican colleagues in the Senate abandoned the historical bipartisan precedent of hearing from witnesses in every impeachment trial. The Senate abandoned its responsibilities when it blocked efforts to get the complete truth.

As a result, there will be a permanent cloud over these proceedings. The president may be acquitted, but without a fair trial he cannot claim to be exonerated.

Alexander Hamilton wrote that impeachment proceedings should concern "the abuse or violation of some public trust." This is the core question of this impeachment trial: Is it OK for the president to use his office to advance his personal political interest, while ignoring or damaging the public good? My answer is no.

Some have argued that although the president used his power to secure an unfair advantage in our elections, that abuse of power isn't bad enough to remove him.

It is that bad. Trump's abuses of power are grave offenses that threaten the constitutional balance of power and our right to free and fair elections. His abuses of power undermine the moral stature of the United States as a trusted ally and a fighter against corruption. If we fail to check this president, future presidents may be emboldened to pursue even more shameless corruption.

Some have said we should let the people decide in the next election, only months away. But when the president solicits foreign nations to influence our elections with disinformation and prevents the public from hearing a full and fair accounting of that effort, our duty to defend the Constitution requires that we act now. When the president shows no remorse and admits he is ready to do it again, we have no choice but to act.

There is nothing inevitable about democracy. It's not a natural state, it's a state we have to fight for. The fight for democracy and our Constitution has chosen us in this moment and it's our job to rise to the moment.

After the Senate vote, the work of reinforcing the American values of fairness and justice will continue. We have a lot of work to do, but democracy is hard work, and I know that Minnesotans are up to it. The truth is that I see more signs of common ground, hope and determination in Minnesota than I do the fractures of division, distrust and partisanship. That is a foundation for us all to build on going forward.

Tina Smith, a Democrat, represents Minnesota in the U.S. Senate.