So I take it that this is just a cheap political grandstand play by the Republicans?
If a meeting was adjourned. It is adjourned. The Democrats did not "walk out" they adjourned the meeting. If the Republicans want to sit in the dark and kevetch, that is their right.
The First Amendment gives the right for the Republicans to peaceably assemble and talk and debate amongst themselves.
A historical event? Doubtful. Republicans being in the dark is neither an event nor historical.
That was nine minutes of my life lost forever.