Texas Rep. Will Hurd, one of six incumbent House Republicans to recently announce their retirement from Congress, said that if an anti-immigrant manifesto being examined by authorities is authenticated, the massacre in El Paso on Saturday may turn out to be an act of terrorism fueled by racism.

"I would leave the analysis of this current activity and this current shooting in El Paso to the FBI. I know they are evaluating it and believing it is possibly a hate crime and fueled by this initial indications of this manifesto that the shooter wrote suggests that. And if it is — in that is indeed confirmed — then yes, this is is white nationalism terrorism," Hurd said on "Face the Nation" Sunday.

Early on Saturday, a gunman went on a shooting rampage inside a Walmart in El Paso, killing at least 20 people and injuring more than two dozen. Local authorities responded to calls of a shooting within minutes and apprehended the suspect, Patrick Crusius, a 21-year-old white man.

Federal investigators are probing the massacre as a possible hate crime and going through a hate-filled, anti-immigrant political manifesto directed at the large and growing Latino community in Texas, two law enforcement sources told CBS News.

At a press conference Sunday morning, U.S. Attorney for Western District of Texas John Bash said his office is treating the shooting as an act of domestic terrorism.

Hurd, who represents a sprawling border district adjacent to El Paso, said that all evidence so far suggests the mass shooting was an act of terrorism.

"This is an act of terrorism and terrorism is an act where you use violence against civilians for a political end. And initial indications suggest that this is based on race and hatred — which would be white nationalist terrorism," he said.

Some high-profile Democrats like Beto O'Rourke, who used to represent El Paso in Congress, and Texas Rep. Joaquin Castro, the chair of the Congressional Hispanic Caucus, have drawn a direct connection between President Trump's anti-immigrant rhetoric and the motives of the suspected shooter, who targeted a predominantly Latino border community that has helped tens of thousands of asylum-seekers just this year.

But Hurd argued the problem underpinning the massacre is much broader.

"He has an opportunity to be the uniter-in-chief and I hope that's the way to go," he said, referring to Mr. Trump, who he has sometimes criticized openly. "But we can't just focus on just one person or just one entity. This is a problem that has many sources and we need to be talking about all those sources and ways that every element of society can work on dealing with this challenge."

Addressing the mass shooting in Dayton, Ohio — which transpired less than 24 hours after the massacre in El Paso and killed nine people — Hurd said it was also important for Congress to pass limited gun violence prevention legislation.

He said a bill to bolster and expand background checks is something that can garner rare bipartisan support on a highly contentious issue.

"We should be preventing from putting guns in the hands of people that shouldn't have them. That's pretty straightforward and simple," Hurd added.