An apparent bipartisan majority of the House Homeland Security Committee on Thursday endorsed the idea of new laws to address domestic terrorism in the wake of last month’s riot at the U.S. Capitol, as experts warned such internal threats would plague the country for decades to come.

Elizabeth Neumann, a former assistant secretary of homeland security for counterterrorism during the Trump administration, warned lawmakers that there is a “high likelihood” that another domestic terrorist attack would occur in the coming months and that the problem would persist “for the next 10 to 20 years.”

Jonathan Greenblatt, head of the Anti-Defamation League, told lawmakers that Jan. 6 had been a “watershed moment for the white supremacist movement,” and that its adherents viewed the Capitol breach as a “victory.”

Their comments came during the committee’s first hearing in its investigation into the riot that has moved House Democrats and 10 Republicans to impeach the now-former president for an unprecedented second time. The panel’s chairman, Rep. Bennie Thompson (D-Miss.), indicated that he expected its probe would result in concrete legislation to punish and dissuade such attacks, and better monitor and regulate the environments in which extremist ideologies proliferate.

“We have to do something,” Thompson said during the hearing. “I’m sure somewhere there will be agreement on specific legislation.”

But although both Democrats and Republicans on the panel showed enthusiasm for select ventures, it is not yet clear where leaders might prioritize their efforts — or if, in the end, they will be able to find enough common ground to avoid political stalemate.

Rep. Michael McCaul (R-Tex.), the committee’s former chairman, joined a bipartisan group of lawmakers calling for legislation to set specific federal penalties for domestic terrorism cases. Such legislation would aim to bring the prosecution of such crimes into parity with laws targeting terrorism that originates overseas — something proponents said would recognize that the threats are equally insidious.

“What happened Jan. 6 just cries out” for such a response, McCaul said. “I think it sends a strong message about where Congress is, that we’re going to treat domestic terrorism on an equal plane as international terrorism.”

Several lawmakers said they also endorse targeting social media companies with legislation meant to hold them accountable when extremist propaganda is circulated on their platforms. Some backed the approach set out in a bill, co-written by Rep. Tom Malinowski (D-N.J.), seeking to overhaul of Section 230 of the Communications Decency Act, the law giving technology companies liability protection from what third parties post on their sites.

“They’ve dragged their feet too long,” Neumann told lawmakers, referring to social media companies and noting that although the preference was to have business “self-correct … we might be at the point where it is needed for Congress to pass legislation to address the problem.”

Despite their unanimous condemnation of the Capitol attack and white supremacy, the experts assembled Thursday were not in lockstep when it came to recommendations for how Congress ought to go about legislating a response. While Greenblatt came with a seven-part plan, including specific legislative recommendations to increase penalties and for funding mitigation activities, Brian Michael Jenkins of the Rand Corp. took the opposite approach, recommending that prosecutors might do best to go after domestic terrorists by leveraging existing statutes.

Even with bipartisan support for new legislation, there are several political pitfalls on the road to passing it. Some House Democrats have accused certain Republican colleagues of aiding and abetting the Capitol rioters, and across the Capitol the parties remain divided over whether then-President Donald Trump is to blame for inciting the attack.

Thursday’s hearing was held against the backdrop of a debate over whether freshman Rep. Marjorie Taylor Greene (R-Ga.) should be ousted from her committee assignments for espousing conspiracy theories Democrats have labeled dangerous. Late Thursday, the House voted largely along party lines to do so after Greene had pushed back against the accusations, calling them a form of thought crime and decrying Democrats for trying to stifle her right to free speech.

The debate appeared to spill over into Thursday’s hearing, as Rep. Andrew S. Clyde of Georgia — also a first-term Republican — suggested that activists were too quick to brand people with unorthodox and even offensive views as extremists.

“Can people not have differing opinions and those opinions not affect the actual work that they do?” Clyde challenged Greenblatt in the hearing’s only testy exchange.

“Fierce debate shouldn’t allow you to dehumanize me or any other person from any minority group,” Greenblatt shot back.