Donald Trump was subpoenaed by the House panel.
Two of the panel's nine members are Republicans who were appointed by McCarthy.
McCarthy's decision not to participate in the investigation was a mistake.
The congressional committee voted to subpoena former President Donald Trump at the end of the January 6 House panel hearing.
The committee's political makeup could have made a difference in the finale.
All but two of the nine members of the House Select Committee were appointed by Nancy Pelosi.
Party expectations were not met by the two GOP members who were appointed to the committee.
It's a decision that members of the GOP started to publicly second-guess in June amid the peak of the panel's public hearings, and one which looks even more foolish following Thursday's ninth hearing.
In retrospect, it's a huge mistake. I believe he would agree.
After Pelosi rejected his first two choices, McCarthy pulled his party's support.
He made sure that the bipartisan panel was staffed by Trump critics and not a sensitive vote for the former president.
McCarthy gave up any chance he had to affect the narrative that the committee has presented or to disrupt its proceedings when he decided not to take it seriously.
McCarthy's representative did not reply to Insider's request.
The makeup of the committee left the Republican party almost entirely in the dark as the panel issued hundreds of subpoenas and presented a slate of damning witness testimony about Trump's actions.
Earlier this summer, Trump slammed McCarthy's decision.
In June, Trump said a bad decision was made. It was a mistake to not have representation on that committee. It was foolish to make that decision.
The committee has built a compelling case for further criminal action against Trump and the hearings have done little to sway public opinion.
"Perhaps the committee's job was never to convince Trump supporters to abandon him so much as it was to build the most effective case they could for additional criminal action," he said.
According to a recent report from The Atlantic, Attorney General Garland could be getting ready for more action against the former president. It's not clear if the DOJ will bring criminal charges against Trump for his role in the attack.
Democrats and Republicans are fighting for control of Congress in a tight election in two years. The long-term impact of the panel may not be fully understood until at least 2024.
History will look back on the panel's work as a way to prevent a grave threat to American if Trump is legally disqualified from running.
That's not certain with Trump constantly teasing a campaign.
Business Insider has an article on it.