A congressional committee next week will begin its investigation into the Capitol insurrection. Everything that has taken place since that day shows just how important it is that they get to the truth.

The broad strokes of what happened before and during that attack on American democracy has been clear from the start. President Trump – and his people in Congress and right-wing media – wound up his supporters for weeks with lies about a stolen election, then invited them to Washington, D.C., telling them the only way to take back their country was to disrupt the counting of the Electoral College votes on Jan. 6.

So when the crowd did exactly that, it could not have been more obvious who was to blame.

We need this congressional inquiry to get at important questions that remain unanswered. How did law enforcement so severely underestimate an attack that was so openly planned in advance? What did the president and his people do as the Capitol was overrun? Why did it take hours for the National Guard to deploy?

Did the Trump administration’s sympathy for the attackers play any role? Just what is the relationship between the Trump White House, the organizers of the rally, and the planners and perpetrators of the attack?

Finally, what does the attack say about this moment in America? Could this kind of violence become a regular part of our politics?

As a country, we desperately need to address these questions and reckon with the answers.

But in the months following the insurrection, Republicans have tried to obscure what really occurred that day. Some blame the riots on disguised members of “antifa.” Sen. Ron Johnson, who in the days after the attack called for a independent investigation into security failures, now says it was a “peaceful protest.” A Republican congressman who can be seen in video from Jan. 6 barricading a door in the Capitol, clearly panicked as rioters rushed in, now says it was nothing more than a “tourist visit.”

And Trump, of course, has continued to press the lie that the election he lost was corrupt. He paints the Jan. 6 protesters as patriots – the same protesters who overwhelmed police lines with violence, beat outnumbered officers with their fists, flagpoles and fire extinguishers, and frantically searched for elected officials once inside the Capitol.

Criminal charges have been filed against more than 400 of these “peaceful” rioters, with more likely to come. About 140 Capitol police officers were injured; some are still out of work. Five people, including a police officer, died that day. Two more officers took their own lives in the days after the insurrection, and others are still suffering from the trauma.

In the months since Jan. 6, we’ve all found out just how scary it was – and how close it came to being much, much worse.

Many of the protesters who came to Washington, D.C., that day had at least some vague intention of pressuring the vice president and Congress against confirming the Electoral College vote.

But others had more specific plans. In the time before Jan. 6, groups organized around white nationalism and conspiracy theories began preparing for something much more than a protest, sharing maps of the Capitol and discussing targets. They spoke explicitly about storming the building and using violence to bring Congress to a halt.

Video at the Capitol on Jan. 6 shows not only throngs of angry but largely aimless protesters, but also organized paramilitary groups with body armor, weapons and communication devices. They can be seen moving through the crowd together, with purpose, at times communicating with other like-minded groups as they prepared to breach the police line.

It was these groups that led the charge into the Capitol, then rushed through the building in a desperate attempt to find their targets.

As bad as it was, it could have been worse. What would have happened had the rioters gotten hold of a member of Congress, or the electoral votes themselves? We’d like to think Republicans would have stood up for democracy and the peaceful transfer of power, but even after the attack, 147 GOP members still voted against certifying the results of a free and fair election – giving the rioters just what they wanted.

So it’s no wonder Republicans want to put this episode behind them, making every attempt to delegitimize any investigation into one of the darkest moments in American democracy.

But the rest of us need to treat Jan. 6 for what it was: A serious, organized and violent attempt to keep Congress from finalizing election results, spurred on by a sitting president and his party.

By obscuring the truth around Jan. 6, we make it all the more likely that something like it will happen again.