White House press secretary Sarah Huckabee Sanders on Oct. 2 said "it would be premature to weigh in" on whether the Las Vegas shooting was an act of domestic terrorism. (Reuters)

For the third time in four months, a tragedy on U.S. soil is dominating the country's attention. And for the third time in four months, we're about to have a debate about whether to label such an act — perpetrated by a man with no known ties to Muslim extremism — as “terrorism.”

Shortly after the Las Vegas shooting that killed at least 58 people and injured more than 500 Sunday night, law enforcement indicated that it was not treating the tragedy as terrorism. “No, not at this point,” Clark County Sheriff Joe Lombardo said. “We believe it was a local individual. He resides here locally. .… We don’t know what his belief system was at this time.”

And White House press secretary Sarah Huckabee Sanders said during Monday's briefing that “it would be premature to weigh in” on whether the shooting was an act of domestic terrorism.

To which plenty of people responded: What? How could the worst mass shooting in modern U.S. history not be terrorism?

The debate has been festering for a while, most notably since June, when a white man attacked congressional Republicans' baseball practice just outside Washington. It returned in August, when an alleged white supremacist drove into a crowd of counterprotesters in Charlottesville. Some on the right wanted a man who targeted Republicans classified as a terrorist, while President Trump's critics noted his failure to label the Charlottesville attacker as such — despite Trump's emphasis on “radical Islamic terrorism.” (The debate also raged back in mid-2015, when a white man with a demonstrated racist past opened fire at a historically black church in Charleston, S.C.)

As of Monday morning, “terrorism” was trending on Twitter, but most lawmakers were not using the t-word — with a few exceptions.

The Democratic National Committee quickly labeled it as “terror” — twice — in a statement from Chairman Tom Perez. Rep. Jim Cooper (D-Tenn.) also called it an “act of terror.” Reps. Katherine M. Clark (D-Mass.) and Elizabeth Esty (D-Conn.) referenced the “terror” in Las Vegas but didn't specifically label the attack as such.

Some Republicans also used the word. Rep. Lee Zeldin (R-N.Y.) called the shooter, who has been identified as Stephen Paddock of Mesquite, Nev., “a domestic terrorist.” Sen. James Lankford (R-Okla.) called it a “despicable act of terror.”

But those are the very few exceptions at this point. The vast majority of members of Congress have responded via tweets and statements without using that word. Perhaps they don't want to get ahead of the evidence, but some argue that this is giving the shooter the benefit of the doubt in a way that simply isn't afforded to Muslims who commit such acts.

Slate's Jamelle Bouie pointed to racism as the cause.

This may seem like a semantic debate. Lots of people are dead and wounded, and a word isn't going to change that. But that word does have all kinds of implications for how these episodes are treated both by the federal government and in our national discourse. It's important.

Rep. Jim Himes (D-Conn.) noted the implications of the debate.

As for the technical definition of terrorism, it importantly deals with the motive rather than the size of the carnage. Federal law says terrorism is “the unlawful use of force and violence against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social objectives.” In other words, whether 50 people are killed or a few people are hurt, what matters is what the attacker intended.

When Muslims commit terrorist attacks, it fits into a clear clash of civilizations that has been playing out for decades. It seems part of a broader war taking place not just in one country, but worldwide, and it aims to inflict — often successfully — fear of similar attacks in the future. Attacks like the ones on Charleston, Charlottesville and suburban Washington don't so easily fit into a large-scale conflict, and the motives of the shooters (especially if they are dead) may be more complicated to ascertain.

But if an attacker is a white supremacist seeking to stoke a “race war” — as Charleston shooter Dylann Roof claimed to be — isn't that attempting to further a “political or social objective?” Roof was charged with hate crimes, but not domestic terrorism. Similarly, the alleged perpetrator of the attack in Charlottesville certainly had a political point of view on race issues and could arguably have been trying to instill fear in other would-be opponents of his movement. The shooter at the congressional GOP baseball practice asked whether the lawmakers present were Republicans before launching his attack, making it seem possible he had a political ax to grind — and a message to send.

It's all very complicated and open to interpretation, but that interpretation is often made rather quickly in the case of attacks by Muslims. And oftentimes the ruling out of terrorism in attacks like Las Vegas seems to be equated with the ruling out of international terrorism or Muslim extremism. Case in point: Lombardo responding to the question by noting the man was a local -- "He resides here locally." But that doesn't technically matter.

And the act in Las Vegas does seem to fit at least one definition of terrorism: the state of Nevada's. Nevada defines an act of terrorism as “any act that involves the use or attempted use of sabotage, coercion or violence which is intended to ... cause great bodily harm or death to the general population.”

That seems to clearly apply to this case; the federal definition is much more difficult to meet. It's also a debate that's completely worth having.