"This appears to be the worst terrorist attack on American soil since 9/11, and it is a sobering reminder that radical Islamists are targeting our country and our way of life," said House Homeland Security Chairman Michael McCaul of Texas. "But Americans will not be intimidated by these fanatics. Instead, tragedies like we saw in Orlando only strengthen our resolve to fight back against terror and prevail over extremism wherever it emerges.”
President Barack Obama used his remarks Sunday afternoon to make yet another call for tighter gun laws, calling it a "further reminder how easy" it is for someone to obtain powerful firearms.
"We have to decide if that’s the kind of country we want to be," he said. "To do nothing is a decision, as well."
Sen. Bob Casey said Sunday that he plans to introduce a bill that would bar someone convicted of hate crimes from purchasing firearms.
The Pennsylvania Democrat plans to meet with lesbian, gay, bisexual, and transgender community leaders in Pittsburgh on Monday to discuss “steps the United States government must take immediately to address safety concerns across the country from commonsense gun laws to ongoing acts of hate,” according to a statement from his office.
"This phenomenon of near constant mass shootings happens only in America — nowhere else," said Sen. Christopher S. Murphy of Connecticut. "Congress has become complicit in these murders by its total, unconscionable deafening silence."
Murphy, a Democrat, represents the state that experienced a horrific mass shooting in 2012 at Sandy Hook Elementary School in Newtown that left 26 dead. Murphy's Senate counterpart, Democrat Richard Blumenthal, also said Senate inaction to prevent gun violence has made lawmakers "complicit in this public health crisis."
But as details began to emerge Sunday morning about the attack, one Republican said the attack could foster debate in both areas.
"A lot of us have been talking for quite a while in terms of background checks and tightening background checks, particularly as it pertains to those with mental illness," Sen. Jeff Flake of Arizona said on NBC's "Meet the Press ." "And I think that that debate can and should go on as well as the debate on how to best protect us against those who were inspired or funded or directed by international terrorists."
A similar dynamic emerged after the mass shooting in San Bernadino, California, in December. The lawmaker representing San Bernadino also weighed in following the Orlando attack.
"Guns — guns designed to kill efficiently and quickly — have no place on our streets," said Rep. Pete Aguilar who represents San Bernardino. The Democrat later added, "We can and we must do better — for Orlando, for San Bernardino and for us all."
Democrats were also more likely to highlight the fact that the attack happened at a gay nightclub. June marks Lesbian, Gay, Bisexual and Transgender Pride Month with scores of events taking place across the country.
"Although the investigation remains ongoing, the fact that it targeted a place where LGBT Americans went to feel safe — and that it occurred during LGBT Pride Month — initially leads to the belief that this was not only an act of terrorism, but also a crime of hate and prejudice," said House Minority Whip Steny H. Hoyer of Maryland.
But some Republicans, including House Intelligence Chairman Devin Nunes of California, and Florida Sen. Marco Rubio did make reference to the nature of the club.
"Clearly radical Islam wants to target the gay community," Nunes told CNN on Sunday morning. "And this would be a prime location to do that.”
John T. Bennett and Lindsey McPherson contributed to this report.