I was one of the 74 million Americans who voted to reelect President Donald Trump, in part because of his administration’s many accomplishments.

Last Saturday, I voted to convict him on the House of Representatives’ article of impeachment. Here’s why.

First, I believe — like many conservative constitutional scholars — the Constitution’s text, context, and precedent authorize an impeachment trial of a former president.

» READ MORE: Pat Toomey cites Trump’s ‘betrayal of the Constitution’ in breaking with GOP on impeachment

Article I, Section 2 grants the House “the sole Power of Impeachment.” Article I, Section 3 grants the Senate “the sole Power to try all Impeachments” [my emphasis]. It is indisputable that the House impeached Donald Trump while he was president for offenses committed while in office. Thus, the Senate’s power “to try all impeachments” includes his.

Furthermore, the founders’ understanding of the term “impeachment” included application to former officials for actions taken in office. Nearly half of the contemporary state constitutions containing impeachment only permitted impeachment trials of former officials. None prohibited them.

Finally, Senate precedent includes impeachment trials for former officials.

For me, then, the question was: Did President Trump’s postelection behavior constitute “high crimes and misdemeanors”?

President Trump’s defense team made several accurate observations at the trial. Many elected Democrats did want to impeach him even before he won the 2016 election, and the mainstream media was unrelentingly hostile toward him. Democrats and the media often overlooked, and sometimes condoned, violent riots when perpetrated in favor of causes they found sympathetic.

But media bias and Democratic hypocrisy do not excuse President Trump’s conduct after he lost the 2020 election.

» READ MORE: The push to punish Pat Toomey points to a future tied to Trump for Pennsylvania Republicans

By Nov. 7, it was clear that absent major reversals in several states, Joe Biden would be the next president. Immediately, President Trump pursued his legal challenges to those results, in all of the swing states where he narrowly lost. I publicly supported his right to do so. He requested three recounts. All confirmed his loss. He filed dozens of lawsuits, but judge after judge — some Trump appointees — rejected his claims of widespread fraud for lack of evidence.

With legitimate challenges exhausted, he turned to legally dubious means to retain power. He pressured state legislatures, including Pennsylvania’s, to overturn state election results, either by refusing to certify them or by installing new electors to vote contrary to their states’ results. He pressured Georgia’s secretary of state to “find” enough votes to reverse the outcome there. This pressure campaign eventually included members of Congress and even Vice President Mike Pence, whom President Trump repeatedly and publicly urged to unilaterally reject electoral slates that cost them reelection. Of course, the vice president has no such authority and, to his credit, he refused to so violate his oath of office.

When these efforts failed, President Trump capitalized on his supporters’ anger, which he had fomented, in a last-ditch effort to retain power. He promoted a rally in Washington, D.C., immediately preceding the meeting where the vice president and Congress would finalize his loss. In a 70-minute speech, he repeated notoriously false charges that a great victory was stolen from them and urged the unruly mob to march to the U.S. Capitol to “Stop the Steal.”

No one should be surprised by what followed. Massively outnumbered, the Capitol Police were overwhelmed and the mob stormed and vandalized the Capitol.

Amidst the ensuing riot, several people died. Officers were pummeled, pushed down stairs, and assaulted with bear and pepper spray. Over 125 sustained physical injuries ranging from concussions and swollen limbs to cracked ribs and smashed spinal discs.

All the while, the president watched. Minutes after learning his vice president had to be removed from the Senate chamber because his life was in danger, Trump tweeted that “Mike Pence didn’t have the courage to do what should have been done to protect our Country and our Constitution.” With the Capitol inundated by rioters, Minority Leader Kevin McCarthy called President Trump, asking for help. The president coldly retorted that the rioters were “more upset about the election than you are.” Even after the dust finally settled, President Trump unthinkably condoned the rioters’ actions: “These are the things and events that happen when a sacred landslide election victory is so unceremoniously & viciously stripped away from great patriots who have been badly & unfairly treated for so long. Go home with love & in peace. Remember this day forever!”

Because of President Trump’s conduct, for the first time in American history, the transfer of presidential power was not peaceful. A president’s lawless effort to retain power was a primary fear motivating the founders’ inclusion of impeachment authorities in the Constitution. President Trump’s desperate attempts to stay in office undermined the foundations of our republic, betrayed the confidence of millions who voted for him, and required a vote to convict.

Pat Toomey is a U.S. senator from Pennsylvania.