Trump tried to obstruct the committee by getting top aides not to cooperate, but other staffers have filled in the gaps.

Politico reported:

Some of the select panel’s most crucial information has come from Trumpworld staffers, who were often in the room or briefed on sensitive meetings, even if they weren’t central players themselves. It’s a classic investigative strategy that’s paid dividends for select committee investigators, many of whom are seasoned, former federal prosecutors.

“We are definitely taking advantage of the fact that most senior-level people in Washington depend on a lot of young associates and subordinates to get anything done,” said Rep. Jamie Raskin (D-Md.), a member of the select committee. “A lot of these people still have their ethics intact and don’t want to squander the rest of their careers for other people’s mistakes and corruption.”

The 1/6 Committee has gotten testimony from aides for Pence, Bannon, Clark, and Meadows, among others, so even if the aides closest to Trump refuse to cooperate, their aides are telling the 1/6 Committee what they need to know.

The 1/6 Committee has done something that other committees failed to do when investigating Trump. They have gotten past the obstruction of Donald Trump by talking to other people who were in the room for meetings and calls.

Without the ability to use executive privilege, Trump can’t stop people from testifying, and that means that the committee doesn’t need the big names because they’ve got the staffers who were working for those doing Trump’s bidding.