WASHINGTON (NewsNation Now) — The bipartisan effort to look into what happened on Jan. 6 at the U.S. Capitol has come to a standstill. Republicans and Democrats can’t agree on who will be on the commission and the scope of the investigation.

The push for a comprehensive, nonpartisan investigation into the Jan. 6 Capitol riot has come to a halt.

“It’s discouraging,” said chairman of the 9/11 Commission Thomas Kean. “Congress can’t seem to get its act together and create a commission because they’re arguing over who should be on it, what the numbers should be between the two parties.”

The former New Jersey governor and former Indiana Rep. Lee Hamilton co-chaired the 9/11 Commission, a now widely recognized successful investigation.

“The 9/11 Commission did not start out with credibility. I think we earned that credibility, not in a month or two, but in a year or two,” Hamilton said.

Lawmakers on both sides of the aisle favor a Jan. 6 commission modeled after Kean and Hamilton’s work.

“What happened from a security standpoint, and how we could’ve prevented it. How we can prevent it in the future,” House Speaker Nancy Pelosi said.

However, Republicans argue that Pelosi’s plan is too broad to include not just what happened on the day of the riot but also deeper inquiries into violent domestic extremism.

They also say that unlike Kean and Hamilton’s commission, Pelosi wants to stack the committee.

“Speaker Pelosi started by proposing a commission that would be partisan by design. Seven appointments for Democrats, just four for Republicans,” Senate minority leader Mitch McConnell said.

It’s been more than a month since Speaker Pelosi proposed the commission. One source told NewsNation the Speaker is still willing to negotiate the details.

Kean says he doesn’t believe Congress has the ability to form a bipartisan commission. Hamilton says he’ll remain optimistic.

“It can be done. For heaven’s sakes we ought not to proceed in the opposite direction,” Hamilton said.

Both men agree that as more time passes from Jan. 6, it may become less of a priority as new issues will take attention in Congress.

More recently, Pelosi floated the idea of having three house committees lead the investigation rather than an independent commission. So far, the Senate’s largely bipartisan investigation has yielded results.