The social media posts of a nondescript-66-year-old-turned-assassin are partisan, profane — and par for the course of what Washington lawmakers (and the reporters who cover them) receive every day.

“We all get death threats,” Rep. Robert Pittenger (R-N.C.) told MSNBC's Hallie Jackson on Wednesday. "[Saying] 'I hate you. You should be dead.'”

What's so terrifying for Washington, still on its knees after a brazen, open-air act of political violence that has left one congressman in critical condition, is this question: Why? Why did this man, who engaged in politics seemingly peacefully by frequently calling his Republican member of Congress's office to disagree and who handed out campaign fliers for Sen. Bernie Sanders in Illinois and, like almost all other liberals, seemed to despise President Trump — decide to gun down Republican members of Congress on an open baseball field?

With the leafy suburban neighborhood still taped off as a crime scene Wednesday, lawmakers on both sides of the aisle had settled on an answer: We need more unity, less partisanship.

But some of their prescriptions on how exactly to do that was shaded by the exact same partisanship they said needed to ease.

To be sure, Washington was capable of providing soothing moments of humanity.

“An attack on one of us is an attack on all of us,” House Speaker Paul D. Ryan (R-Wis.) said, to a standing ovation by the full House of Representatives.

“You're going to hear me say something you've never heard me say before,” followed House Minority Leader Nancy Pelosi (D-Calif.). “I identify myself with the remarks of the speaker.”

Ryan: 'An attack on one of us is an attack on all of us' (U.S. House of Representatives)

Later that day at a news conference at the Capitol, the manager of the Democrats' baseball team, Rep. Mike Doyle (D-Pa.), invited his counterpart on the Republicans' team to dinner. Rep. Joe Barton (R-Tex.), who survived the shooting along with his two sons, accepted. “I may bring a food taster,” Barton joked.

But partisanship did not, has not evaporated. Remember those racist fliers plastered on car windshields and utility poles in this Alexandria neighborhood a couple of weeks ago, recalled Rep. Don Beyer (D-Va.), who represents the city where the shooting happened and had arrived at the crime scene to get a briefing from police.

A few minutes later, an SUV pulled up, and out came Rep. Steve King (R-Iowa) — about as far away from a liberal as you can find in Washington — to offer up this: “America has been divided. And the center of America is disappearing, and the violence is appearing in the streets, and it's coming from the left.”

Then, former House speaker Newt Gingrich, a fixture on cable news these days, explained the shooting this way on Fox: “It's part of a pattern. You've had an increasing intensity of hostility on the left.”

When asked about that Thursday, Pelosi was incredulous:

"I think the comments made by my Republican colleagues are outrageous, beneath the dignity of the job they hold," she said, pointing to any number of anti-Pelosi TV ads that she said has led to constant calls to her home and threats to her face, with her granchildren standing there. " ... How dare they say such a thing? How dare they?"

Pelosi slams 'outrageous' accusations from Republicans about Democrats' rhetoric (Reuters)

The tension Pelosi is getting at: If extreme partisanship played a role in the shooting, neither side is innocent.

But neither side seems completely capable of letting go of their grievances. And this is exactly the opposite of what a frayed nation needs right now, said Alan Lipman, a psychiatrist and director of the Center of the Study of Violence. It's bad enough that lawmakers are assigning blame across the aisle for the fact that a man none of them knew decided to point a gun at their colleagues.

It's even worse when lawmakers and their supporters do it while, in the same breath, calling for unity. They're essentially hollowing out the meaning of the word, he said.

Lipman: “The tragic irony of what's happening this morning is that each side, in attempting to argue for unity and recognition of the heat of incendiary polarization, so often cannot resist characterizing only their political opponents as the cause — thereby perpetuating the very polarization and angry one-sided characterizations that they purport to heal.”

“We can't call for unity while at the same time painting one side in the same enraged, broad-brush strokes as the cause,” Lipman continued. “This is fueling the hard, long road of the cure with the disease.”

The reality is that everyone in Washington is horrified by this attack, and almost everyone agrees that something in the tone and demeanor with which Washington does daily business needs to change.

But very few here actually believe this moment will be that turning point.

Right now, partisanship is muscle memory. It's a path so well worn that it's the only one lawmakers and the people who voted for/against them can see to take, even when they say there needs to be less of it.

And that's why this shooting is so scary: It derived from the most ordinary of political commentary, of the flavor lawmakers receive every day. Washington thinks it knows the problem, but it can't seem to even start a conversation about out how to fix it.