G: The naming problem is interesting because the best name probably shouldn't contain “political violence.” That describes the subject accurately, but it makes the holiday sound like it's about politics rather than about a civic boundary Americans are agreeing to defend.

A few first-pass candidates:

• National Civic Peace Day — Probably my strongest initial candidate. “Civic” makes clear this concerns public and political life without assigning ideology; “peace” makes the desired behavior explicit. The weakness is that it can sound slightly generic.
• Day of Civic Remembrance — More solemn and memorial-like. It puts victims first and leaves the prevention/anti-rhetoric mission to the holiday's official description. Very difficult to construe as partisan.
• American Civic Peace Day — “American” gives it a mildly patriotic register that may make it harder for the right to dismiss as institutional euphemism, while “civic peace” isn't particularly conservative or progressive.
• National Day of Civic Unity — Strong rhetorically, although unity risks implying that people are supposed to agree politically. Your actual principle is more interesting: we can remain bitterly divided without treating violence as legitimate.
• Civic Peace and Remembrance Day — Less elegant, but unusually accurate: remember the dead and injured and reinforce the norm against political violence.
• American Peaceful Democracy Day — Captures the prevention side, but “democracy” has unfortunately acquired enough partisan loading that I'd rank this below the civic formulations.
• Day of the Peaceful Republic — This one is somewhat unconventional, but I like the underlying idea. It frames nonviolence not as niceness or political correctness but as something necessary to maintaining a republic.
• National Day Against Political Violence — Maximally clear and almost impossible to misunderstand. But I'd probably reject it precisely because it names the contested thing rather than the shared value.

There's also a naming direction I think is worth exploring further: “Civic Peace.” It has an unusually useful implication. It doesn't mean political agreement. It means something closer to:

We fight over the country with ballots, arguments, organizing, protest, law, and persuasion—not political violence.

That allows somebody on the hard left and somebody on the hard right to participate without being asked to soften their beliefs, forgive their opponents, or pretend the country is unified. They're only agreeing to a rule about how political conflict is conducted.

So for a first round, my three strongest are National Civic Peace Day, Day of Civic Remembrance, and Civic Peace and Remembrance Day. Of those, National Civic Peace Day strikes me as having the most room to become culturally natural after people have heard it a few times.

G: I agree with the direction. “Civic” is doing useful work because it points toward our shared political/public life without specifying which politics. And “remembrance” establishes victims as the center of gravity rather than the perpetrators or ideological dispute.

Building outward from Civic Remembrance, I'd try:

• National Day of Civic Remembrance — probably the safest formal version. Sounds immediately like a real federal observance and doesn't prejudge what lesson someone must draw.
• Civic Remembrance Day — cleaner everyday name. It also abbreviates naturally without sounding bureaucratic.
• National Civic Remembrance Day — slightly more declarative and patriotic-sounding than “Day of,” while remaining neutral.
• Day of American Civic Remembrance — “American” anchors it specifically in the country's shared history, although it's a little cumbersome.
• National Day of Civic Memory — more distinctive, but “memory” feels less explicitly respectful toward victims than “remembrance.”
• Civic Remembrance and Peace Day — makes the prospective purpose explicit, although I think adding “peace” actually weakens the elegance.
• Civic Remembrance and Renewal Day — interesting if the holiday is meant to include an affirmative recommitment to peaceful political participation. “Renewal,” though, could acquire ideological baggage depending on how it's presented.
• Day of Civic Reflection — gentler and potentially very broad, but it loses the explicit memorial function.

One variant I'd particularly keep in the working pile is National Day of Civic Remembrance, with Civic Remembrance Day as its ordinary short name. That gives you something useful legislatively:

Formal: National Day of Civic Remembrance
Colloquial: Civic Remembrance Day

And there may be an advantage to not putting “violence,” “victims,” “unity,” “democracy,” or “peace” in the title at all. The enabling language can define civic remembrance as honoring Americans harmed or killed by politically motivated violence and reaffirming peaceful political engagement. The title itself then remains remarkably difficult for either side to treat as an accusation.

“Civic” also gives you room to include victims who don't fit neatly into assassination or terrorism categories—officeholders, protesters, journalists, bystanders, election workers, activists, and ordinary citizens—without constantly litigating terminology.

G: Right—the desired emotional register is probably deliberately vanilla: solemn without being funereal, reflective without implying collective guilt, and preventative without sounding like an advocacy campaign.

If we add reflection as a function rather than necessarily a word, these strike me as the strongest next batch:

• Civic Remembrance Day — still the benchmark. Remembrance naturally implies reflection without ordering people what to think.
• National Day of Civic Remembrance and Reflection — exceptionally neutral and accurately describes the intended activity, but rather governmental-sounding.
• Civic Reflection Day — clean, but too broad by itself. You could reasonably wonder whether you're supposed to reflect on the Constitution, voting, citizenship, or something else.
• Civic Remembrance and Reflection Day — probably the most literal complete description. Slightly clunky, but federal-holiday names can survive that.
• National Civic Remembrance — dropping Day gives it an interesting Memorial Day–like conceptual quality. The observance itself becomes “the national civic remembrance.”
• American Civic Remembrance Day — adds a little warmth/patriotic ownership without changing the underlying proposition.
• Day of Civic Memory and Reflection — more contemplative, but I think memory is inferior to remembrance: memory is something you possess; remembrance is something you do.
• Civic Remembrance and Recommitment Day — captures your preventive objective especially well: remember what happened, consider why, and recommit to not doing it again. But recommitment is edging toward ceremonial/political-program language.

There's a semantic structure emerging that I think is more important than the exact title:

Remembrance → Reflection → Restraint.

Remember the people.
Reflect on what brought us there.
Exercise restraint in our actions and rhetoric so we don't produce the next names being remembered.

I wouldn't necessarily put any of those latter two words in the holiday's name. In fact, Civic Remembrance Day may work precisely because the title carries only the first step while the observance establishes the other two.

And restraint might be particularly valuable conceptually. You're not asking Americans for unity, civility, moderation, or even reconciliation. People remain perfectly entitled to think their political opponents are catastrophically wrong. The requested boundary is much narrower: don't help turn political conflict into political violence.

That narrowness may actually be what makes the holiday politically survivable.